A kidney stone typically causes intense, sharp pain in your side and back, just below your ribs. In patient surveys, people rate their worst kidney stone pain at an average of 7.9 out of 10, putting it on par with childbirth. But the experience isn’t just one type of pain in one location. It shifts, builds in waves, and can produce a surprising range of sensations depending on where the stone is in your urinary tract.
Where the Pain Starts
A kidney stone can sit in your kidney for weeks, months, or even years without causing any symptoms at all. The trouble begins when it moves. Once a stone shifts out of the kidney and enters one of the ureters (the narrow tubes connecting each kidney to your bladder), it can block urine flow, cause the kidney to swell, and trigger the ureter to spasm. That’s when the pain hits.
The initial pain usually lands in your flank, the area between your lower ribs and hip on the affected side. Many people describe it as a deep, gripping sensation that feels like it’s coming from inside the body rather than from the surface. It can be sharp and stabbing or start as a dull ache that rapidly intensifies. The pain often radiates to your back, lower abdomen, or groin, which is why some people initially mistake it for a pulled muscle, a stomach problem, or even appendicitis.
The Wave Pattern
One of the most distinctive features of kidney stone pain is that it comes in waves. You might have 20 to 60 minutes of escalating, intense pain followed by a period of relief, only for it to return. The pain typically peaks one to two hours after it starts. In severe cases, the waves can last even longer, and the relief between them may be brief.
This wave pattern happens because the ureter is a muscular tube that contracts rhythmically, trying to push the stone along. Each contraction squeezes the stone against the narrow walls and temporarily increases the blockage, which spikes the pain. When the muscle relaxes, the pressure eases and so does the sensation. People often describe it as pain that “rolls” or “pulses,” and many say they can’t find any position that makes it better. Unlike back pain or muscle injuries, lying down, sitting, or standing doesn’t change the intensity.
How the Pain Moves as the Stone Moves
The location of your pain is a rough map of where the stone is in your urinary tract. As the stone travels down the ureter toward the bladder, the pain often shifts. What started as flank pain may migrate to your lower abdomen and then into your groin. This migration can happen over hours or days, and the character of the pain can change too, becoming more intense or taking on a different quality as the stone reaches narrower sections of the ureter.
Once the stone reaches the lower ureter near the bladder, many people start feeling urinary symptoms: a sudden, urgent need to urinate, needing to go more frequently than normal, or a burning sensation when urinating. You might also notice blood in your urine, which can range from a faint pink tinge to a more visible red or brown color. Once the stone drops into the bladder itself, the worst pain usually ends. Passing it from the bladder out of the body typically takes a few days and is far less painful, though you may feel some stinging or pressure.
Pain Differences Between Men and Women
The core experience is largely the same regardless of sex. The one notable difference occurs when the stone reaches the lower ureter near the bladder. In men, the pain can extend into the groin or scrotum, and some men report a stinging sensation at the tip of the penis. In women, the pain may radiate into the labia and can feel similar to a menstrual cramp. These differences are purely about anatomy: the nerves serving the lower ureter overlap with those serving the reproductive organs, so the brain interprets the signals slightly differently depending on the body.
Small Stones Can Hurt Just as Much
One of the most counterintuitive things about kidney stones is that size doesn’t predict how much they hurt. A study of 650 patients published in The Journal of Urology found no association between stone size and pain scores. A 2-millimeter stone can cause the same excruciating pain as a much larger one. The location of the stone in the ureter didn’t predict pain levels either. What drives the pain is less about the stone’s dimensions and more about how much it obstructs urine flow and how forcefully the ureter spasms in response. So if someone tells you their stone was small and therefore “shouldn’t have hurt that much,” the clinical evidence says otherwise.
Symptoms Beyond Pain
Kidney stones aren’t just a pain experience. The intensity of the pain itself often triggers nausea and vomiting, because the nerves serving the kidneys and ureters are closely linked to those controlling the gut. Many people feel restless and unable to stay still during an episode, pacing or shifting constantly in a way that looks very different from someone with, say, a back injury who wants to stay perfectly motionless.
Other common symptoms include:
- Cloudy or foul-smelling urine, which can signal irritation or the beginning of an infection
- Blood in the urine, caused by the stone scraping the lining of the ureter
- A persistent need to urinate with very little output, especially as the stone nears the bladder
- Chills and fever, which suggest the blockage has led to an infection and require urgent medical attention
What Silent Kidney Stones Feel Like
Not every kidney stone announces itself with dramatic pain. Stones that stay in the kidney and don’t move into the ureter often cause no symptoms at all. These “silent” stones are frequently discovered by accident during imaging for something else entirely. Some people with non-obstructing stones report a vague, dull ache in their side that comes and goes, but nothing close to the acute pain of a stone actively passing through the ureter. This is why the timing of symptoms matters: the pain of a kidney stone is almost always tied to movement and obstruction, not just the stone’s existence.
How It Compares to Other Pain
People who have experienced kidney stones consistently rank the pain among the worst they’ve felt. A 2016 survey of 287 kidney stone patients found an average worst-pain rating of 7.9 out of 10. For comparison, a Scandinavian study asked first-time mothers to rate their worst labor pain, and the average fell between 7 and 8 on the same scale. Mothers who had given birth before rated it slightly lower, at 6 to 7. The numbers put kidney stone pain and labor pain in essentially the same range, which matches the common comparison people make. The key difference is duration: labor pain builds over hours with a clear endpoint, while kidney stone episodes can strike suddenly, resolve, and then return unpredictably over days.