What Causes the Pain of Kidney Stones?

Kidney stones are urinary tract blockages known for causing a lot of pain, but it's the blockage itself (not the sharpness of the stones) that does it. Learn more in this episode of BrainStuff, based on this article: https://health.howstuffworks.com/human-body/systems/kidney-urinary/kidney-stone-pain.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff, a production of iHeart Radio, Hey
brain Stuff. Lauren vogebon here. Mark Bird of Miami, Florida
was thirty eight years old when he had his first
kidney stones. The pain started in his back, like he
had slipped a disk. Bird was used to back pain,

(00:22):
so he tried his standard routine of stretching, yoga, and
frequent trips to the chiropractor, but nothing helped. Then one day,
he was sitting in his office chair when it felt
like someone had sneaked up behind him and stabbed him
in the back of the bowie knife for the article.
This episode is based on hows to work? Spoke Bird
when he was forty eight and the veteran of two

(00:43):
excruciating kidney stone episodes. He said, the pain takes your
breath away. You're doubled over and thinking I need to
get to the hospital right now. Every year, half a
million people visit emergency rooms in the United States with
kidney's tones, and around one in ten Americans will have
a kidney stone at some point in their life. We

(01:06):
humans typically have two kidneys, and their main job is
to filter waste products out of our blood. Normally, those
waste products are flushed out of the kidney as urine.
Your kidneys filter some fifty gallons that's nine liters of
blood every twenty four hours and eliminate some sixty four
ounces or two leads of waste. In some cases, however,

(01:29):
there are excess waste products in the blood that aren't
flushed out of the kidneys. Those leftover waste products can
form tiny crystals that bunched together over time to form
increasingly large stones. Calcium oxalate is the most common component
of kidney stones, but there are others too, including uric acid, struvite,
and sistine. The real trouble starts when one of these

(01:53):
stones leaves the kidney and enters the uritor, which is
a narrow tube that transports urine from the kidney to
the ladder. That's when it can feel like you've been
stabbed in the back. Pain is a hard thing to quantify,
but the discomfort of passing a kidney stone is routinely
compared to childbirth or worse. But the source of that

(02:15):
pain may be surprising. How stuff works. Also spoke with
Dr Timothy Average, a kidney stone specialist at Prisma Health
Urology in Columbia, South Carolina. He said, the common belief
is that the stone itself causes the pain. Patients will
frequently say it must have a lot of rough edges
or spikes because this one hurts a lot, or it's

(02:36):
really large and that's what hurts so badly. That actually
has nothing to do with the pain. So if it's
not the stone, what the heck is causing that searing pain.
The thing is that if a kidney stone is large enough,
it'll get stuck in the narrow passageway of the uritor,
causing urine to build up behind it. With nowhere to go,

(02:58):
the urine exerts increasing pressure on the narrow eutor and
on the kidney, causing the tissues to stretch like balloons.
Average explained that stretching is what triggers the pain people
feel when they have kidney stones. You feel it in
your back first, and then it can radiate around the
front and down to the groin. It's pretty excruciating for

(03:20):
most and the body has all types of nerves for
sensing things like touch and temperature. The nerves and your
kidney in eutor detect distension or dilation, just like your intestines, bladder,
and bowels. An obstructed bowel is also very painful, but
kidney stones are far more common. The discomfort of kidney

(03:43):
stones is described as colic since it comes in waves.
That's because the orator uses involuntary wave like muscle movements
called peristalsis to move urine from the kidney to the
bladder in packets or bunches. If the pathway is blocked,
the pressure builds with every involuntary squeeze of the urotor,
and so does the pain. In both women and men.

(04:07):
Urine exits the bladder through the urethra and then out
from the body. Another common misconceptions as average is that
the most painful part of having a kidney stone is
passing it through the urethra, but he says those fears
are largely unfounded. He said the urethra and men and
women is much wider than the eurotor, almost twice the size.

(04:29):
Patients will frequently say to me, oh, I'll know one,
I pay it out. Often they actually don't. Bird, for
his part, disagrees. Even though treatment for his kidney stones
involved internally blasting them with shock waves to break them
into smaller particles, the largest fragments were still the size
of bebes. A bird says it felt like urinating and

(04:50):
I quote shards of glass. One of the many unpleasant
surprises of Bird's ordeal was that he had to have
a stent in aserted into his eudor to open the
passageway from the kidney to the bladder, and the stent
stayed in for two long weeks. Ural stents are ten
fifteen inch plastic tubes that's around that are inserted through

(05:14):
the urethra all the way up to the kidney to
let urine flow to the bladder again. A stent is
used in many kidney stone removals to keep the order
from becoming obstructed again by swelling. After the operation is complete,
Insertion of the stent is done under heavy sedation. But
removal isn't, a bird said, the nurses try to use

(05:35):
the element of surprise. They pull it out like a
rip chord. Today's episode is based on the article kidney
stones are excruciating, but the source of pain is surprising
on how stuff works dot Com, written by Dave Bruise.
A brain Stuff is production of by Heart Radio in
partnership with how stuff works dot Com and it's produced

(05:55):
by Tyler Klang. Before more podcasts from my heart Radio,
visit the heart Radio app, up Apple podcasts, or wherever
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