July 11, 2025 • 18 mins
Feeling constantly exhausted—even after a full night’s sleep? Chronic fatigue is often dismissed as stress or aging, but it’s usually your body waving a red flag. In this episode of The Health Pulse, we uncover the often-missed medical causes of persistent fatigue and the tests that can finally bring answers.
We explore how low ferritin levels can leave you energy-depleted even when standard iron panels look fine, and why TSH-only thyroid testing often fails to detect real dysfunction. You'll learn about hidden micronutrient deficiencies (like B12, folate, and vitamin D), the impact of cortisol imbalances, and how insulin resistance can silently sap your energy long before blood sugar becomes abnormal.
This is your guide to asking better questions, ordering the right labs, and finally understanding what your fatigue is really trying to tell you. If you’re ready to stop guessing and start solving, this episode is your first step toward lasting energy and clarity.
📞 Need lab work done from the comfort of home? QLM offers fast, reliable mobile phlebotomy services—no clinic visit required.
📅 Book your appointment or learn more at:
👉 Quick Lab Mobile
📧 Contact us: info@quicklabmobile.com
💬 Enjoyed the episode? Leave us a review and let us know what topics you'd like us to cover next! Your feedback helps us bring you the content that matters most.
Disclaimer: The information provided in this podcast is for informational purposes only and should not be considered medical advice. The content discussed is based on research, expert insights, and reputable sources, but it does not replace professional medical consultation, diagnosis, or treatment. We strive to present accurate and up-to-date information, medical research is constantly evolving. Listeners should always verify details with trusted health organizations, before making any health-related decisions. If you are experiencing a medical emergency, such as severe pain, difficulty breathing, or other urgent symptoms, call your local emergency services immediately. By listening to this podcast, you acknowledge that The Health Pulse and its creators are not responsible for any actions taken based on the content of this episode. Your health and well-being should always be guided by the advice of qualified medical professionals.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Nicolette (00:01):
Welcome to the Health Pulse, your go-to source for
quick, actionable insights onhealth, wellness and diagnostics
.
Whether you're looking tooptimize your well-being or stay
informed about the latest inmedical testing, we've got you
covered.
Join us as we break down keyhealth topics in just minutes.
Let's dive in.
Rachel (00:29):
Welcome to the Deep Dive .
Okay, so we've all been there,right?
That feeling after a crazy weekor maybe a terrible night's
sleep where you just feelcompletely drained.
Oh, absolutely that bone-tiredfeeling, yeah.
But what if that feeling, youknow, never really lifts?
What if you wake up tired?
You stay tired and it feelslike you're running on fumes
pretty much every day, no matterhow much sleep you think you're
getting.
Well, today we're doing a deepdive into exactly that
(00:53):
Understanding chronic fatigue,Not just seeing it as like a bad
mood or something, but as areally crucial signal your body
might be sending.
Mark (01:01):
That's a great way to put it, a signal.
Rachel (01:03):
So our mission today, looking at current research and
clinical stuff, is to unpacksome of the most common reasons
why people feel so persistentlytired, specifically the things
that well targeted lab tests canactually reveal.
The goal is really to help yougo from just guessing, or maybe
just enduring it, to actuallyknowing what might be going on.
Mark (01:23):
Yeah, and it's such an important topic because,
honestly, fatigue is soincredibly common.
But, it often gets brushedaside.
People think, oh, I'm juststressed, or I just need a
vacation, or coffee, or morecoffee, exactly, but fatigue
itself.
It's not really a diagnosis,it's more of a downstream effect
(01:44):
.
There could be dozens ofdifferent root causes, these
upstream issues and finding theright tests.
Well, that's how you figure outwhich upstream issue is your
issue.
It really helps you go from,like you said, guessing to
knowing.
Rachel (01:55):
Absolutely.
And maybe a little pro tip foreveryone listening right at the
start If this fatigue, this deeptiredness, has been dragging on
for longer than, say, threeweeks, or if it's really getting
in the way of your work or yourmood, maybe even, just, you
know, getting some exercise,yeah, it's probably time to stop
just trying to push through.
It's really time to test.
Mark (02:15):
Agreed.
Pushing through often just digsthe hole deeper.
Rachel (02:18):
So let's jump in.
Let's explore how specific labtests can start to uncover these
real culprits behind thatexhaustion.
Mark (02:26):
Let's do it.
Rachel (02:27):
Okay.
So when we're talking energy,where do we often start looking
first in the body?
I know one really common andthankfully often treatable cause
for fatigue is anemia,specifically iron deficiency
anemia.
Mark (02:40):
Yes, definitely a primary suspect.
Rachel (02:42):
We know iron's crucial for hemoglobin right Carrying
oxygen everywhere.
But what's something peoplemight miss?
Even listeners who are prettyhealth savvy like maybe their
standard hemoglobin test looksfine.
Mark (02:55):
That is such a key point.
The nuance here is critical.
Hemoglobin tells you about theoxygen your blood is carrying
right now.
Rachel (03:02):
Okay.
Mark (03:03):
But it doesn't necessarily tell you about your iron
reserves.
Lots of people I mean lots canhave normal hemoglobin levels on
a test but feel absolutelywiped out.
Rachel (03:12):
Why is that?
Mark (03:13):
Because their ferritin level, which is the protein that
stores iron in your body, isscraping the bottom of the
barrel.
Rachel (03:18):
Ah, the storage tank is empty.
Mark (03:20):
Exactly, and standard lab ranges for ferritin can be well
incredibly wide.
Some Exactly, and standard labranges for ferritin can be well
incredibly wide.
Some labs might call anythingover 10 gm normal 10?
Rachel (03:28):
Wow, that seems low.
If you're feeling fatigued.
Mark (03:30):
It really is For optimal energy, for good brain function,
especially if fatigue is themain complaint.
We're often looking forferritin levels, you know, maybe
closer to 70 ngml or evenhigher in some cases 70.
Rachel (03:43):
Okay, that's a big difference from 10.
Mark (03:45):
Huge difference.
A low ferritin means your bodyis already running on its backup
generator, dipping into thosereserves, and those reserves can
get really depleted long beforeyour hemoglobin actually drops
into the anemic range on thestandard test.
Rachel (03:58):
That's a super important distinction.
Okay, so let's say someonechecks the ferritin, optimizes
their iron, their oxygendelivery seems okay, but they're
still dragging.
Where do we look next?
The body's main energyregulator, maybe the thyroid?
Mark (04:11):
Yep.
The thyroid is absolutely thenext major stop on the fatigue
investigation tour.
It controls metabolism, bodytemperature, energy levels.
It's hugely important.
Rachel (04:21):
We know it's critical, but what's a common maybe red
herring here, something thatmight make someone think their
thyroid is fine, even when it'sthe root cause of their fatigue?
Mark (04:32):
Well, the biggest one, honestly, is relying solely on
the TSH test thyroid stimulatinghormone.
Rachel (04:37):
Right, that's often the first, sometimes the only one
checked.
Mark (04:40):
Exactly, and the problem is TSH isn't actually a thyroid
hormone itself, it's a hormonefrom the pituitary gland telling
the thyroid what to do.
Rachel (04:50):
Okay, so it's like the manager, not the worker.
Mark (04:52):
Kind of yeah.
Rachel (04:53):
Yeah.
Mark (04:53):
You can have a TSH level that falls within the quote
unquote normal range, but youstill feel exhausted.
Maybe you're gaining weight,have brain fog because your body
isn't actually making enough ofthe active thyroid hormones, or
it isn't converting themproperly or your cells aren't
using them effectively.
Rachel (05:09):
So what should be tested then?
Mark (05:11):
This is why testing free T3 and free T4 is so crucial.
Those are the hormones that areactually unbound, circulating
and available for your tissuesto use.
T4 is the main storage form andT3 is the more potent active
form.
You need to see both Got itFree T3 and free.
T4 is the main storage form andT3 is the more potent active
form you need to see both Got itFree T3 and free T4.
Rachel (05:28):
And what about the autoimmune side of things?
We hear about Hashimoto's quitea bit in relation to thyroid
issues.
Mark (05:34):
Yes, hashimoto's thyroiditis.
It's incredibly common,probably the most common cause
of hypothyroidism, certainly inplaces like the US, and it's
where your own immune systemmistakenly attacks your thyroid
gland.
Rachel (05:46):
Okay, and how does that relate to fatigue?
If the TSH might still lookokay?
Mark (05:51):
Well, what's really interesting and kind of sneaky
is that the autoimmune attackcan start years, literally years
, before your TSH level goessignificantly high enough to
trigger a hypothyroidismdiagnosis based on standard
ranges.
Rachel (06:03):
Wow, years.
Yeah, during that time, as thethyroid is being slowly, damaged
to trigger a hypothyroidismdiagnosis based on standard
ranges.
Mark (06:06):
Wow, Years, yeah.
During that time, as thethyroid is being slowly damaged,
you might experiencefluctuating symptoms periods of
intense fatigue, maybe someweight gain, feeling cold,
alternating sometimes withperiods where you might feel a
bit anxious or jittery, almostlike hyperthyroidism, as the
damaged gland releases storedhormone, so it can be confusing.
Very confusing and this isprecisely why testing thyroid
(06:27):
antibodies, specificallyanti-TPO and anti-TG antibodies,
is so important.
They're direct markers of thatautoimmune attack.
If those antibodies areelevated, it's a very strong
indicator you're dealing withHashimoto's, even if your TSH is
still technically normal, andknowing that completely changes
how you'd approach managing thefatigue and the underlying
immune issue.
(06:47):
It also makes you think aboutother things like gut health,
because there's a strong gutthyroid connection.
Rachel (06:53):
Okay, that makes a lot of sense.
So, beyond iron and thyroid,these sort of big hormonal
players, sometimes the fatiguemight boil down to like the
basic building blocks the bodyneeds to even make energy right,
exactly Like if someone'sstruggling with brain fog, along
with fatigue or maybe low mood,even some weird nerve
sensations.
What are the key micronutrientswe should be thinking about?
Mark (07:15):
Absolutely.
Think of it like this you canhave fuel like iron for oxygen
and the accelerator pedalworking like the thyroid, but
you also need the right sparkplugs to actually ignite the
energy.
Rachel (07:27):
Good analogy.
Mark (07:28):
Three huge ones for energy production and nerve function
are vitamin B12, folate andvitamin D.
Rachel (07:33):
Okay, b12, folate, vitamin D let's take B12 first
and D let's take B12 first.
Mark (07:37):
Right, b12 and folate.
They work together reallyclosely.
They're essential for makinghealthy red blood cells so
there's an overlap with anemiathere but also for DNA synthesis
and, really importantly, for aprocess called methylation.
Rachel (07:48):
Methylation.
Okay, what does that do forenergy?
Mark (07:56):
Methylation is fundamental .
It's involved in gosh hundredsof processes, including making
neurotransmitters, detoxifyinghormones and critically turning
genes on and off and producingenergy at the cellular level.
So a deficiency in B12 orfolate can lead directly to
fatigue, weakness, sometimeseven neurological symptoms like
numbness, tingling or memoryproblems, even if your iron
levels are totally fine.
Rachel (08:15):
And I've heard, b12 absorption can sometimes be an
issue for people right, even ifthey eat enough B12-rich foods.
Oh, issue for people right,like even if they eat enough B12
rich foods?
Mark (08:22):
Oh, definitely, it's quite common.
Things like low stomach acid,using acid blocking medications
like PPIs, long term gut issueslike Crohn's or celiac disease,
even certain genetic variations,can really impair your ability
to absorb B12 from food or evenstandard supplements, and this
is where standard testing cansometimes fall short.
Again, just looking at serumB12 doesn't always tell you if
(08:45):
the B12 is actually getting intothe cells and doing its job.
Rachel (08:48):
What's a better way to check?
Mark (08:50):
Often, clinicians will also look at a marker called
methylmalonic acid or MMA.
Mma levels tend to go up whenyour body doesn't have enough
functional B12 at the cellularlevel, so it gives you a more
functional picture of B12 status.
Rachel (09:04):
MMA.
Good to know.
And what about folate?
Is there a better way to testthat too?
Mark (09:08):
Similarly for folate.
Yeah, Serum folate canfluctuate a lot depending on
what you ate recently.
A more stable long-termindicator is often considered to
be RBC folate, or red bloodcell folate.
It reflects your body's folatestores over the lifespan of your
red blood cells about threemonths.
Rachel (09:23):
Okay, rbc folate Got it.
And then the third one youmentioned was vitamin D.
That seems to come upeverywhere these days.
Mark (09:29):
It really does, and for good reason.
It acts much more like ahormone than just a simple
vitamin.
It's involved in immunefunction, bone health, obviously
, mood regulation and criticallyfor this conversation the
actual function of yourmitochondria.
Those are little powerhousesinside your cells that generate
energy.
Rachel (09:46):
Right, the energy factories.
Mark (09:48):
Exactly so.
Low vitamin D levels arestrongly linked to fatigue,
muscle aches and pains, weaknessand even symptoms of depression
, and deficiency is incrediblywidespread.
Especially for those of us notliving near the equator and even
symptoms of depression anddeficiency is incredibly
widespread, Especially for thoseof us not living near the
equator.
Precisely If you live innorthern latitudes, have darker
(10:08):
skin pigmentation or just don'tget much safe sun exposure, your
risk is much higher.
But the good news is, like B12and folate, once you identify a
vitamin D deficiency, the testyou want is 25-hydroxyvitamin D.
It's usually prettystraightforward to correct with
appropriate supplementation andmonitoring.
These are foundational piecesfor energy.
Rachel (10:26):
Foundational.
Yeah, okay, so we've coverediron, thyroid, key vitamins.
But even if all those levelslook pretty good, sometimes it
feels like just well, modernlife itself is the biggest
energy drain.
Let's talk about stress.
How does chronic stress reallyimpact energy beyond just
feeling, you know, mentallyfrazzled?
Mark (10:43):
Oh, it's profound.
It's absolutely not just inyour head your body's stress
response system, which is mainlygoverned by the hormone
cortisol produced by youradrenal glands.
Rachel (10:53):
Right Cortisol.
Mark (10:54):
That system is deeply, deeply connected to your energy
regulation, your blood sugarbalance, your immune function,
sleep cycles, everything.
Rachel (11:02):
So what happens when that system gets out of whack
from, say, constant pressure?
Mark (11:07):
Well, when cortisol is out of balance and that could mean
it's consistently too high, ormaybe it drops too low, or maybe
the daily rhythm is justcompletely off-den your energy
levels will absolutely suffer.
Rachel (11:18):
How so?
What does that feel like?
Mark (11:19):
Initially, with acute or early chronic stress, cortisol
might stay elevated.
That can lead to that classicfeeling of being wired but tired
.
You might have trouble fallingasleep, feel anxious, maybe
crave sugar or salt.
Rachel (11:31):
Yeah, I know that feeling.
Mark (11:32):
But if that stress continues relentlessly over a
long period, the system canstart to sort of fatigue itself
becomes less responsive.
Period the system can start tosort of fatigue itself becomes
less responsive.
This is sometimes referred toinformally as adrenal fatigue,
though in a more accurate termis HPA axis, dysregulation,
hypothalamic, pituitary adrenalaxis.
Rachel (11:50):
HPA axis dysregulation Okay.
Mark (11:53):
In this later stage, cortisol production might
actually dip, especially attimes when it should be higher,
like in the morning.
This leaves you feelingprofoundly flat, foggy-headed,
unmotivated, just completelyburned out and unable to cope
with even minor stressors.
Rachel (12:10):
So it's not just about how much cortisol you have
overall, but also the patternthroughout the day.
Mark (12:15):
Exactly.
That's the crucial part that asingle blood draw often misses.
A one-time blood cortisol test,usually done in the morning,
only gives you a tiny snapshotRight.
What's much more revealing isdoing a diurnal cortisol panel.
This typically involvescollecting saliva or sometimes
dried urine samples at severalpoints throughout the day, like
upon waking, maybe mid-morning,afternoon and before bed.
Rachel (12:36):
Okay, tracking a rhythm.
Mark (12:38):
Precisely.
It shows you your cortisolrhythm.
Is it peaking nicely in themorning to help you wake up and
feel energized.
Does it gradually declinethroughout the day?
Does it reach its lowest pointat night so you can sleep
restfully?
That natural curve is vital forsustained energy.
Rachel (12:52):
And if that curve is off , like flat or high at night.
Mark (12:55):
If it's off, maybe it's flatline low all day, maybe it
spikes erratically or stays highat night.
That directly correlates withsymptoms like persistent fatigue
, insomnia, afternoon energycrashes or feeling oddly wired
when you should be winding down.
A diurnal cortisol test canprovide really profound insights
if stress seems like a majorfactor in your fatigue.
Rachel (13:16):
That makes a lot of sense, okay.
And finally, there's one morebig area you mentioned that can
really drive your fatigue.
That makes a lot of sense, okay.
And finally, there's one morebig area you mentioned that can
really drive chronic fatigue,and it's one maybe people don't
immediately connect unless theyhave a specific diagnosis Blood
sugar.
Mark (13:28):
Yes, Blood sugar dysregulation.
This is huge and often fliesunder the radar for a long time.
We're not just talking aboutfull-blown diabetes here.
Many, many people experiencesignificant fatigue, brain fog,
irritability and those intenseenergy crashes because of
underlying insulin resistance,often years before their blood
(13:48):
sugar levels rise high enoughfor a type 2 diabetes diagnosis.
Rachel (13:50):
Insulin resistance.
Can you break that down quickly?
How does that cause fatigue?
Mark (13:54):
Sure.
So normally when you eatcarbohydrates, your blood sugar
goes up.
Your pancreas releases insulinwhich acts like a key, unlocking
your cells to let that sugar infor energy.
Okay, with insulin resistanceyour cells become well resistant
to that key.
They don't respond as well toinsulin's signal, so sugar
struggles to get into the cellswhere it's needed for fuel.
Rachel (14:16):
Ah, so the fuel isn't getting delivered properly.
Mark (14:18):
Exactly, and your pancreas tries to compensate by pumping
out more and more insulin to tryand force the doors open.
This leads to high insulinlevels in the blood and that
causes problems.
It causes a cascade of problems.
First you get this rollercoaster effect.
Maybe a big surge of sugar getsinto the cells eventually, or
the high insulin drives bloodsugar down too low later on.
This causes those classicsymptoms feeling exhausted after
(14:41):
meals, intense cravings forsugar or carbs, that dreaded 3
pm energy slump the slump, yesand brain fog too, because your
brain relies heavily on stableglucose.
What's really critical tounderstand here is that your
fasting glucose, the standardtest, and even your HbA1c, which
measures average blood sugarover about three months, those
(15:01):
can both look perfectly normalfor years, maybe even a decade,
while this underlying insulinresistance and high insulin
situation is brewing and makingyou feel terrible.
Rachel (15:12):
Wow, so those standard tests aren't catching the early
problem.
Mark (15:16):
Often not the earliest signs.
No, the real early warning signis often elevated fasting
insulin.
Rachel (15:20):
Is fasting insulin.
Mark (15:22):
If your fasting insulin level is high, even with normal
fasting glucose, it's a huge redflag.
It tells you your body'salready working way too hard
compensating to keep your bloodsugar stable.
That chronic metabolic effortis incredibly taxing and is a
major, major driver of fatiguefor so many people.
Rachel (15:39):
So if someone suspects blood sugar issues might be part
of their fatigue puzzle, theyshould ask for fasting insulin
specifically, not just glucoseor A1C.
Mark (15:47):
Absolutely.
Insist on it.
Don't just check fastingglucose and A1C.
Add fasting insulin to thatpanel.
It provides such valuableinformation about your metabolic
health and can be a completegame changer in understanding
persistent fatigue cravings andenergy instability.
Rachel (16:03):
That's incredibly helpful.
Ok, so we've covered a lot ofground here Iron, thyroid
vitamins, cortisol, blood sugar.
So, pulling it all together,what's the main takeaway?
For someone listening who justfeels tired all the time?
Yeah, what does it all mean foryou, right, exactly, I think
the core message has to befeeling exhausted constantly.
Isn't something you just haveto accept or normalize.
(16:25):
It's not just about needingmore sleep, although sleep is
important, or, you know,doubling down on caffeine.
Fatigue, especially when it'schronic like this is, is really
a symptom.
It's your body sending up aflare signaling that something
deeper needs attention.
Mark (16:40):
Beautifully put.
It's a signal.
And just to quickly recap theareas we touched on we talked
about optimizing iron stores,looking beyond just hemoglobin
to ferritin.
We discussed getting a completethyroid picture, including free
T3, free T4, and thyroidantibodies, not just TSH.
We covered foundationalnutrients like B12, folate and
vitamin D and why functionaltesting might be needed Yep.
(17:02):
We talked about assessing yourstress response with diurnal
cortisol testing to understandyour HPA axis function.
And finally, looking beyondbasic glucose checks to fasting
insulin to catch early bloodsugar dysregulation and insulin
resistance.
Rachel (17:16):
That's a great summary.
Mark (17:18):
And the key point through all of this is that the answers,
or at least the crucial clues,are so often found in your labs.
Getting the right test donegives you real, objective data.
Rachel (17:28):
Yeah.
Mark (17:28):
And that knowledge is incredibly empowering.
It allows you to stop theguesswork and actually start a
targeted journey towards healing, towards figuring out your
specific puzzle and, ultimately,reclaiming your energy.
Rachel (17:39):
Absolutely, it puts you back in the driver's seat.
So maybe a final thought toleave everyone with building on
that idea of taking action.
If your body is sending thatsignal, that fatigue flare you
mentioned, what deeper insights,what missing pieces of your
unique energy puzzle might yourown lab results reveal?
Mark (17:57):
It's a powerful question to ask yourself.
Rachel (17:59):
It really is.
Keep asking those questions,keep seeking those answers and
keep diving deep intounderstanding your own health.
Nicolette (18:10):
Thanks for tuning into the Health Pulse.
If you found this episodehelpful, don't forget to
subscribe and share it withsomeone who might benefit.
For more health insights anddiagnostics, visit us online at
wwwquicklabmobilecom.
Stay informed, stay healthy andwe'll catch you in the next
episode.
Welcome to the Health Pulse, your go-to source for
quick, actionable insights onhealth, wellness and diagnostics
.
Whether you're looking tooptimize your well-being or stay
informed about the latest inmedical testing, we've got you
covered.
Join us as we break down keyhealth topics in just minutes.
Let's dive in.
Rachel (00:29):
Welcome to the Deep Dive .
Okay, so we've all been there,right?
That feeling after a crazy weekor maybe a terrible night's
sleep where you just feelcompletely drained.
Oh, absolutely that bone-tiredfeeling, yeah.
But what if that feeling, youknow, never really lifts?
What if you wake up tired?
You stay tired and it feelslike you're running on fumes
pretty much every day, no matterhow much sleep you think you're
getting.
Well, today we're doing a deepdive into exactly that
(00:53):
Understanding chronic fatigue,Not just seeing it as like a bad
mood or something, but as areally crucial signal your body
might be sending.
Mark (01:01):
That's a great way to put it, a signal.
Rachel (01:03):
So our mission today, looking at current research and
clinical stuff, is to unpacksome of the most common reasons
why people feel so persistentlytired, specifically the things
that well targeted lab tests canactually reveal.
The goal is really to help yougo from just guessing, or maybe
just enduring it, to actuallyknowing what might be going on.
Mark (01:23):
Yeah, and it's such an important topic because,
honestly, fatigue is soincredibly common.
But, it often gets brushedaside.
People think, oh, I'm juststressed, or I just need a
vacation, or coffee, or morecoffee, exactly, but fatigue
itself.
It's not really a diagnosis,it's more of a downstream effect
(01:44):
.
There could be dozens ofdifferent root causes, these
upstream issues and finding theright tests.
Well, that's how you figure outwhich upstream issue is your
issue.
It really helps you go from,like you said, guessing to
knowing.
Rachel (01:55):
Absolutely.
And maybe a little pro tip foreveryone listening right at the
start If this fatigue, this deeptiredness, has been dragging on
for longer than, say, threeweeks, or if it's really getting
in the way of your work or yourmood, maybe even, just, you
know, getting some exercise,yeah, it's probably time to stop
just trying to push through.
It's really time to test.
Mark (02:15):
Agreed.
Pushing through often just digsthe hole deeper.
Rachel (02:18):
So let's jump in.
Let's explore how specific labtests can start to uncover these
real culprits behind thatexhaustion.
Mark (02:26):
Let's do it.
Rachel (02:27):
Okay.
So when we're talking energy,where do we often start looking
first in the body?
I know one really common andthankfully often treatable cause
for fatigue is anemia,specifically iron deficiency
anemia.
Mark (02:40):
Yes, definitely a primary suspect.
Rachel (02:42):
We know iron's crucial for hemoglobin right Carrying
oxygen everywhere.
But what's something peoplemight miss?
Even listeners who are prettyhealth savvy like maybe their
standard hemoglobin test looksfine.
Mark (02:55):
That is such a key point.
The nuance here is critical.
Hemoglobin tells you about theoxygen your blood is carrying
right now.
Rachel (03:02):
Okay.
Mark (03:03):
But it doesn't necessarily tell you about your iron
reserves.
Lots of people I mean lots canhave normal hemoglobin levels on
a test but feel absolutelywiped out.
Rachel (03:12):
Why is that?
Mark (03:13):
Because their ferritin level, which is the protein that
stores iron in your body, isscraping the bottom of the
barrel.
Rachel (03:18):
Ah, the storage tank is empty.
Mark (03:20):
Exactly, and standard lab ranges for ferritin can be well
incredibly wide.
Some Exactly, and standard labranges for ferritin can be well
incredibly wide.
Some labs might call anythingover 10 gm normal 10?
Rachel (03:28):
Wow, that seems low.
If you're feeling fatigued.
Mark (03:30):
It really is For optimal energy, for good brain function,
especially if fatigue is themain complaint.
We're often looking forferritin levels, you know, maybe
closer to 70 ngml or evenhigher in some cases 70.
Rachel (03:43):
Okay, that's a big difference from 10.
Mark (03:45):
Huge difference.
A low ferritin means your bodyis already running on its backup
generator, dipping into thosereserves, and those reserves can
get really depleted long beforeyour hemoglobin actually drops
into the anemic range on thestandard test.
Rachel (03:58):
That's a super important distinction.
Okay, so let's say someonechecks the ferritin, optimizes
their iron, their oxygendelivery seems okay, but they're
still dragging.
Where do we look next?
The body's main energyregulator, maybe the thyroid?
Mark (04:11):
Yep.
The thyroid is absolutely thenext major stop on the fatigue
investigation tour.
It controls metabolism, bodytemperature, energy levels.
It's hugely important.
Rachel (04:21):
We know it's critical, but what's a common maybe red
herring here, something thatmight make someone think their
thyroid is fine, even when it'sthe root cause of their fatigue?
Mark (04:32):
Well, the biggest one, honestly, is relying solely on
the TSH test thyroid stimulatinghormone.
Rachel (04:37):
Right, that's often the first, sometimes the only one
checked.
Mark (04:40):
Exactly, and the problem is TSH isn't actually a thyroid
hormone itself, it's a hormonefrom the pituitary gland telling
the thyroid what to do.
Rachel (04:50):
Okay, so it's like the manager, not the worker.
Mark (04:52):
Kind of yeah.
Rachel (04:53):
Yeah.
Mark (04:53):
You can have a TSH level that falls within the quote
unquote normal range, but youstill feel exhausted.
Maybe you're gaining weight,have brain fog because your body
isn't actually making enough ofthe active thyroid hormones, or
it isn't converting themproperly or your cells aren't
using them effectively.
Rachel (05:09):
So what should be tested then?
Mark (05:11):
This is why testing free T3 and free T4 is so crucial.
Those are the hormones that areactually unbound, circulating
and available for your tissuesto use.
T4 is the main storage form andT3 is the more potent active
form.
You need to see both Got itFree T3 and free.
T4 is the main storage form andT3 is the more potent active
form you need to see both Got itFree T3 and free T4.
Rachel (05:28):
And what about the autoimmune side of things?
We hear about Hashimoto's quitea bit in relation to thyroid
issues.
Mark (05:34):
Yes, hashimoto's thyroiditis.
It's incredibly common,probably the most common cause
of hypothyroidism, certainly inplaces like the US, and it's
where your own immune systemmistakenly attacks your thyroid
gland.
Rachel (05:46):
Okay, and how does that relate to fatigue?
If the TSH might still lookokay?
Mark (05:51):
Well, what's really interesting and kind of sneaky
is that the autoimmune attackcan start years, literally years
, before your TSH level goessignificantly high enough to
trigger a hypothyroidismdiagnosis based on standard
ranges.
Rachel (06:03):
Wow, years.
Yeah, during that time, as thethyroid is being slowly, damaged
to trigger a hypothyroidismdiagnosis based on standard
ranges.
Mark (06:06):
Wow, Years, yeah.
During that time, as thethyroid is being slowly damaged,
you might experiencefluctuating symptoms periods of
intense fatigue, maybe someweight gain, feeling cold,
alternating sometimes withperiods where you might feel a
bit anxious or jittery, almostlike hyperthyroidism, as the
damaged gland releases storedhormone, so it can be confusing.
Very confusing and this isprecisely why testing thyroid
(06:27):
antibodies, specificallyanti-TPO and anti-TG antibodies,
is so important.
They're direct markers of thatautoimmune attack.
If those antibodies areelevated, it's a very strong
indicator you're dealing withHashimoto's, even if your TSH is
still technically normal, andknowing that completely changes
how you'd approach managing thefatigue and the underlying
immune issue.
(06:47):
It also makes you think aboutother things like gut health,
because there's a strong gutthyroid connection.
Rachel (06:53):
Okay, that makes a lot of sense.
So, beyond iron and thyroid,these sort of big hormonal
players, sometimes the fatiguemight boil down to like the
basic building blocks the bodyneeds to even make energy right,
exactly Like if someone'sstruggling with brain fog, along
with fatigue or maybe low mood,even some weird nerve
sensations.
What are the key micronutrientswe should be thinking about?
Mark (07:15):
Absolutely.
Think of it like this you canhave fuel like iron for oxygen
and the accelerator pedalworking like the thyroid, but
you also need the right sparkplugs to actually ignite the
energy.
Rachel (07:27):
Good analogy.
Mark (07:28):
Three huge ones for energy production and nerve function
are vitamin B12, folate andvitamin D.
Rachel (07:33):
Okay, b12, folate, vitamin D let's take B12 first
and D let's take B12 first.
Mark (07:37):
Right, b12 and folate.
They work together reallyclosely.
They're essential for makinghealthy red blood cells so
there's an overlap with anemiathere but also for DNA synthesis
and, really importantly, for aprocess called methylation.
Rachel (07:48):
Methylation.
Okay, what does that do forenergy?
Mark (07:56):
Methylation is fundamental .
It's involved in gosh hundredsof processes, including making
neurotransmitters, detoxifyinghormones and critically turning
genes on and off and producingenergy at the cellular level.
So a deficiency in B12 orfolate can lead directly to
fatigue, weakness, sometimeseven neurological symptoms like
numbness, tingling or memoryproblems, even if your iron
levels are totally fine.
Rachel (08:15):
And I've heard, b12 absorption can sometimes be an
issue for people right, even ifthey eat enough B12-rich foods.
Oh, issue for people right,like even if they eat enough B12
rich foods?
Mark (08:22):
Oh, definitely, it's quite common.
Things like low stomach acid,using acid blocking medications
like PPIs, long term gut issueslike Crohn's or celiac disease,
even certain genetic variations,can really impair your ability
to absorb B12 from food or evenstandard supplements, and this
is where standard testing cansometimes fall short.
Again, just looking at serumB12 doesn't always tell you if
(08:45):
the B12 is actually getting intothe cells and doing its job.
Rachel (08:48):
What's a better way to check?
Mark (08:50):
Often, clinicians will also look at a marker called
methylmalonic acid or MMA.
Mma levels tend to go up whenyour body doesn't have enough
functional B12 at the cellularlevel, so it gives you a more
functional picture of B12 status.
Rachel (09:04):
MMA.
Good to know.
And what about folate?
Is there a better way to testthat too?
Mark (09:08):
Similarly for folate.
Yeah, Serum folate canfluctuate a lot depending on
what you ate recently.
A more stable long-termindicator is often considered to
be RBC folate, or red bloodcell folate.
It reflects your body's folatestores over the lifespan of your
red blood cells about threemonths.
Rachel (09:23):
Okay, rbc folate Got it.
And then the third one youmentioned was vitamin D.
That seems to come upeverywhere these days.
Mark (09:29):
It really does, and for good reason.
It acts much more like ahormone than just a simple
vitamin.
It's involved in immunefunction, bone health, obviously
, mood regulation and criticallyfor this conversation the
actual function of yourmitochondria.
Those are little powerhousesinside your cells that generate
energy.
Rachel (09:46):
Right, the energy factories.
Mark (09:48):
Exactly so.
Low vitamin D levels arestrongly linked to fatigue,
muscle aches and pains, weaknessand even symptoms of depression
, and deficiency is incrediblywidespread.
Especially for those of us notliving near the equator and even
symptoms of depression anddeficiency is incredibly
widespread, Especially for thoseof us not living near the
equator.
Precisely If you live innorthern latitudes, have darker
(10:08):
skin pigmentation or just don'tget much safe sun exposure, your
risk is much higher.
But the good news is, like B12and folate, once you identify a
vitamin D deficiency, the testyou want is 25-hydroxyvitamin D.
It's usually prettystraightforward to correct with
appropriate supplementation andmonitoring.
These are foundational piecesfor energy.
Rachel (10:26):
Foundational.
Yeah, okay, so we've coverediron, thyroid, key vitamins.
But even if all those levelslook pretty good, sometimes it
feels like just well, modernlife itself is the biggest
energy drain.
Let's talk about stress.
How does chronic stress reallyimpact energy beyond just
feeling, you know, mentallyfrazzled?
Mark (10:43):
Oh, it's profound.
It's absolutely not just inyour head your body's stress
response system, which is mainlygoverned by the hormone
cortisol produced by youradrenal glands.
Rachel (10:53):
Right Cortisol.
Mark (10:54):
That system is deeply, deeply connected to your energy
regulation, your blood sugarbalance, your immune function,
sleep cycles, everything.
Rachel (11:02):
So what happens when that system gets out of whack
from, say, constant pressure?
Mark (11:07):
Well, when cortisol is out of balance and that could mean
it's consistently too high, ormaybe it drops too low, or maybe
the daily rhythm is justcompletely off-den your energy
levels will absolutely suffer.
Rachel (11:18):
How so?
What does that feel like?
Mark (11:19):
Initially, with acute or early chronic stress, cortisol
might stay elevated.
That can lead to that classicfeeling of being wired but tired
.
You might have trouble fallingasleep, feel anxious, maybe
crave sugar or salt.
Rachel (11:31):
Yeah, I know that feeling.
Mark (11:32):
But if that stress continues relentlessly over a
long period, the system canstart to sort of fatigue itself
becomes less responsive.
Period the system can start tosort of fatigue itself becomes
less responsive.
This is sometimes referred toinformally as adrenal fatigue,
though in a more accurate termis HPA axis, dysregulation,
hypothalamic, pituitary adrenalaxis.
Rachel (11:50):
HPA axis dysregulation Okay.
Mark (11:53):
In this later stage, cortisol production might
actually dip, especially attimes when it should be higher,
like in the morning.
This leaves you feelingprofoundly flat, foggy-headed,
unmotivated, just completelyburned out and unable to cope
with even minor stressors.
Rachel (12:10):
So it's not just about how much cortisol you have
overall, but also the patternthroughout the day.
Mark (12:15):
Exactly.
That's the crucial part that asingle blood draw often misses.
A one-time blood cortisol test,usually done in the morning,
only gives you a tiny snapshotRight.
What's much more revealing isdoing a diurnal cortisol panel.
This typically involvescollecting saliva or sometimes
dried urine samples at severalpoints throughout the day, like
upon waking, maybe mid-morning,afternoon and before bed.
Rachel (12:36):
Okay, tracking a rhythm.
Mark (12:38):
Precisely.
It shows you your cortisolrhythm.
Is it peaking nicely in themorning to help you wake up and
feel energized.
Does it gradually declinethroughout the day?
Does it reach its lowest pointat night so you can sleep
restfully?
That natural curve is vital forsustained energy.
Rachel (12:52):
And if that curve is off , like flat or high at night.
Mark (12:55):
If it's off, maybe it's flatline low all day, maybe it
spikes erratically or stays highat night.
That directly correlates withsymptoms like persistent fatigue
, insomnia, afternoon energycrashes or feeling oddly wired
when you should be winding down.
A diurnal cortisol test canprovide really profound insights
if stress seems like a majorfactor in your fatigue.
Rachel (13:16):
That makes a lot of sense, okay.
And finally, there's one morebig area you mentioned that can
really drive your fatigue.
That makes a lot of sense, okay.
And finally, there's one morebig area you mentioned that can
really drive chronic fatigue,and it's one maybe people don't
immediately connect unless theyhave a specific diagnosis Blood
sugar.
Mark (13:28):
Yes, Blood sugar dysregulation.
This is huge and often fliesunder the radar for a long time.
We're not just talking aboutfull-blown diabetes here.
Many, many people experiencesignificant fatigue, brain fog,
irritability and those intenseenergy crashes because of
underlying insulin resistance,often years before their blood
(13:48):
sugar levels rise high enoughfor a type 2 diabetes diagnosis.
Rachel (13:50):
Insulin resistance.
Can you break that down quickly?
How does that cause fatigue?
Mark (13:54):
Sure.
So normally when you eatcarbohydrates, your blood sugar
goes up.
Your pancreas releases insulinwhich acts like a key, unlocking
your cells to let that sugar infor energy.
Okay, with insulin resistanceyour cells become well resistant
to that key.
They don't respond as well toinsulin's signal, so sugar
struggles to get into the cellswhere it's needed for fuel.
Rachel (14:16):
Ah, so the fuel isn't getting delivered properly.
Mark (14:18):
Exactly, and your pancreas tries to compensate by pumping
out more and more insulin to tryand force the doors open.
This leads to high insulinlevels in the blood and that
causes problems.
It causes a cascade of problems.
First you get this rollercoaster effect.
Maybe a big surge of sugar getsinto the cells eventually, or
the high insulin drives bloodsugar down too low later on.
This causes those classicsymptoms feeling exhausted after
(14:41):
meals, intense cravings forsugar or carbs, that dreaded 3
pm energy slump the slump, yesand brain fog too, because your
brain relies heavily on stableglucose.
What's really critical tounderstand here is that your
fasting glucose, the standardtest, and even your HbA1c, which
measures average blood sugarover about three months, those
(15:01):
can both look perfectly normalfor years, maybe even a decade,
while this underlying insulinresistance and high insulin
situation is brewing and makingyou feel terrible.
Rachel (15:12):
Wow, so those standard tests aren't catching the early
problem.
Mark (15:16):
Often not the earliest signs.
No, the real early warning signis often elevated fasting
insulin.
Rachel (15:20):
Is fasting insulin.
Mark (15:22):
If your fasting insulin level is high, even with normal
fasting glucose, it's a huge redflag.
It tells you your body'salready working way too hard
compensating to keep your bloodsugar stable.
That chronic metabolic effortis incredibly taxing and is a
major, major driver of fatiguefor so many people.
Rachel (15:39):
So if someone suspects blood sugar issues might be part
of their fatigue puzzle, theyshould ask for fasting insulin
specifically, not just glucoseor A1C.
Mark (15:47):
Absolutely.
Insist on it.
Don't just check fastingglucose and A1C.
Add fasting insulin to thatpanel.
It provides such valuableinformation about your metabolic
health and can be a completegame changer in understanding
persistent fatigue cravings andenergy instability.
Rachel (16:03):
That's incredibly helpful.
Ok, so we've covered a lot ofground here Iron, thyroid
vitamins, cortisol, blood sugar.
So, pulling it all together,what's the main takeaway?
For someone listening who justfeels tired all the time?
Yeah, what does it all mean foryou, right, exactly, I think
the core message has to befeeling exhausted constantly.
Isn't something you just haveto accept or normalize.
(16:25):
It's not just about needingmore sleep, although sleep is
important, or, you know,doubling down on caffeine.
Fatigue, especially when it'schronic like this is, is really
a symptom.
It's your body sending up aflare signaling that something
deeper needs attention.
Mark (16:40):
Beautifully put.
It's a signal.
And just to quickly recap theareas we touched on we talked
about optimizing iron stores,looking beyond just hemoglobin
to ferritin.
We discussed getting a completethyroid picture, including free
T3, free T4, and thyroidantibodies, not just TSH.
We covered foundationalnutrients like B12, folate and
vitamin D and why functionaltesting might be needed Yep.
(17:02):
We talked about assessing yourstress response with diurnal
cortisol testing to understandyour HPA axis function.
And finally, looking beyondbasic glucose checks to fasting
insulin to catch early bloodsugar dysregulation and insulin
resistance.
Rachel (17:16):
That's a great summary.
Mark (17:18):
And the key point through all of this is that the answers,
or at least the crucial clues,are so often found in your labs.
Getting the right test donegives you real, objective data.
Rachel (17:28):
Yeah.
Mark (17:28):
And that knowledge is incredibly empowering.
It allows you to stop theguesswork and actually start a
targeted journey towards healing, towards figuring out your
specific puzzle and, ultimately,reclaiming your energy.
Rachel (17:39):
Absolutely, it puts you back in the driver's seat.
So maybe a final thought toleave everyone with building on
that idea of taking action.
If your body is sending thatsignal, that fatigue flare you
mentioned, what deeper insights,what missing pieces of your
unique energy puzzle might yourown lab results reveal?
Mark (17:57):
It's a powerful question to ask yourself.
Rachel (17:59):
It really is.
Keep asking those questions,keep seeking those answers and
keep diving deep intounderstanding your own health.
Nicolette (18:10):
Thanks for tuning into the Health Pulse.
If you found this episodehelpful, don't forget to
subscribe and share it withsomeone who might benefit.
For more health insights anddiagnostics, visit us online at
wwwquicklabmobilecom.
Stay informed, stay healthy andwe'll catch you in the next
episode.
Popular Podcasts
Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.