Ask anyone who has been through it, and they’ll probably give you a look that suggests they’ve seen things no human should see. If you’re currently sitting on your bathroom floor or pacing the living room wondering is it painful to pass kidney stones, the short answer is yes. For many, it is. But "painful" is a bit of an understatement. Doctors and patients frequently rank the sensation right alongside childbirth or a gunshot wound.
It’s a specific kind of agony. It isn't like a muscle cramp or a bad stomach ache. It’s a deep, visceral, "I can’t find a comfortable position" type of misery.
Why a tiny crystal causes so much drama
You’d think something the size of a grain of salt wouldn’t be able to drop a grown adult to their knees. But the human anatomy wasn't exactly designed to move jagged rocks through delicate plumbing. Kidney stones, or nephrolithiasis if you want to be formal, are basically hard deposits of minerals and acid salts. They stick together in concentrated urine. When they stay in the kidney, you usually don't feel a thing. You could have a stone the size of a marble hanging out in your renal pelvis right now and be totally oblivious.
The nightmare begins the moment that stone decides to travel.
The ureter is the tube connecting your kidney to your bladder. It is tiny. It is narrow. It is also extremely sensitive. When a stone enters this tube, it does two things that trigger the "pain of a thousand suns." First, the jagged edges of the stone—which often looks like a piece of coral under a microscope—can scrape the lining of the ureter. Second, and more importantly, the stone can get stuck and block the flow of urine. This causes the kidney to stretch.
💡 You might also like: That Weird Feeling in Knee No Pain: What Your Body Is Actually Trying to Tell You
This stretching, or hydronephrosis, is what sends those frantic signals to your brain. Your body realizes something is very wrong, and it reacts with waves of intense pressure and sharp stabs.
The "Renal Colic" rollercoaster
Doctors call this specific type of pain renal colic. It’s not a steady throb. Instead, it comes in waves. You might feel fine for twenty minutes, thinking the ordeal is finally over, only to be hit by a fresh surge that makes you want to crawl out of your own skin.
Where you feel it depends entirely on where the stone is located at that exact second.
- The Flank: This is the classic starting point. You'll feel it in your back or side, just below the ribs. It’s a deep, heavy ache that radiates forward.
- The Abdomen: As the stone moves down the ureter, the pain migrates. It travels toward your belly.
- The Groin and Genitals: This is often the most confusing part for people. As the stone nears the bladder, men might feel intense pain in their testicles, while women feel it in the labia. It’s referred pain—your nerves are basically misfiring because the stone is irritating the lower part of the urinary tract.
It isn't just about the back pain
Honestly, the pain is only half the story. The systemic response is what usually sends people to the ER. When the pain hits a certain threshold, your nervous system goes into overdrive.
📖 Related: Does Birth Control Pill Expire? What You Need to Know Before Taking an Old Pack
Nausea is almost universal. Vomiting is common. You might find yourself drenched in a cold sweat even if the room is freezing. Then there's the "urgency." You’ll feel like you have to pee every thirty seconds, but when you try, only a few drops come out. Or worse, what comes out looks like iced tea or fruit punch because of the blood.
Size matters, but maybe not how you think
There is a common misconception that a bigger stone always equals more pain. Not necessarily.
A 2mm stone can be excruciating if it has sharp, crystalline spikes and gets wedged perfectly in a narrow bend of the ureter. Conversely, some people pass 5mm stones with nothing more than a dull ache and a "ping" in the toilet bowl. However, once a stone gets north of 6mm, the odds of it passing on its own drop significantly. According to the Urology Care Foundation, stones smaller than 4mm have an 80% chance of passing solo. Once you hit 5mm, it’s a coin flip.
If a stone is too big to move, it can cause a "silent" obstruction. This is actually dangerous. If you have a dull ache that never goes away, it might mean the stone is stuck and the kidney is under constant pressure, which can lead to permanent damage or infection.
👉 See also: X Ray on Hand: What Your Doctor is Actually Looking For
Managing the "Passing" process
So, how do you actually get through it? If you're at home trying to pass a stone, hydration is your only real job. You want to flush the system. But don't chug a gallon of water in ten minutes; that can actually increase the pressure and the pain. Slow, steady sipping is the way to go.
Medical intervention has come a long way from the "grin and bear it" days.
- Alpha-blockers: Drugs like Tamsulosin (Flomax) are a godsend. They were originally for prostate issues, but they work by relaxing the muscles in your ureter. This gives the stone more "room" to wiggle through.
- Pain Management: Over-the-counter NSAIDs like Ibuprofen or Naproxen are often more effective than heavy opioids for kidney stones. They reduce the inflammation in the ureter, which helps the stone slide.
- The "Jump and Bump": It sounds like a TikTok trend, but some urologists actually suggest light jumping or movement to help gravity pull the stone down. Just don't do it if you're dizzy from the pain.
When the pain becomes a medical emergency
Most kidney stones are a "wait and see" situation. You stay home, you take your meds, you pee through a strainer to catch the evidence. But there are lines you shouldn't cross.
If you develop a fever or chills, get to the hospital immediately. That is a sign of an infection trapped behind the stone. An infected, obstructed kidney is a legitimate medical emergency that can lead to sepsis. Also, if the pain is so severe that you can't keep fluids or pain medication down because of vomiting, you need an IV.
What to do next: A practical checklist
If you suspect you have a stone, don't just wait for it to "go away."
- Start a "Fluid Log": Track how much you're drinking. Aim for 2-3 liters a day unless a doctor tells you otherwise.
- Get a Strainer: You need to catch the stone. If you catch it, a lab can analyze it. Knowing if it's calcium oxalate, uric acid, or struvite determines exactly how to prevent the next one.
- Watch the Scale: Rapid weight gain or swelling in your legs while dealing with a stone can indicate your kidneys aren't processing fluid correctly.
- Schedule an Imaging Test: You need to know the size. An ultrasound or a non-contrast CT scan is the gold standard. Knowing you’re fighting a 3mm stone is a lot more encouraging than finding out you're trying to pass a 9mm boulder that will never fit.
- Adjust Your Diet: Once the crisis passes, look at your salt intake. Sodium is a primary driver of calcium stones. Cutting back on processed foods is usually the first piece of advice any urologist will give you.
The process of passing a stone is a test of endurance. It's miserable, it's exhausting, and it's scary. But once that stone finally hits the bladder, the relief is almost instantaneous. The "work" is done, and the final stretch through the urethra is—mercifully—usually the easiest part.