Kidney stones in women typically announce themselves with sudden, intense pain between the ribs and hip on one side of the body that comes in waves. The pain often radiates downward toward the groin or deep into the pelvis as the stone moves, and it’s frequently accompanied by blood in the urine. But because these symptoms overlap with several gynecological conditions, recognizing kidney stones as a woman can be trickier than you might expect.
Where the Pain Shows Up
The hallmark of a kidney stone is renal colic: severe, intermittent pain in the flank (the area between your lower ribs and hip) that builds in waves rather than staying constant. The location shifts as the stone travels. A stone still near the kidney produces deep back or side pain. As it moves into the middle portion of the ureter (the tube connecting your kidney to your bladder), pain can wrap around toward the front of your abdomen. Once a stone reaches the lower ureter near the bladder, it often radiates into the groin, the labia, or deep in the pelvis.
This migrating pain is one of the clearest signals. Unlike a pulled muscle or cramp that stays in one spot, kidney stone pain tends to shift over hours or days as the stone works its way down. The intensity can be extreme, often described as sharper and more stabbing than other abdominal pain, and it rarely responds well to changing positions. You can’t get comfortable.
Urinary Changes to Watch For
Blood in the urine is one of the most telling signs. It shows up in 75 to 95% of women with kidney stones during active episodes. Sometimes the blood is visible, turning urine pink, red, or brownish. Other times it’s microscopic and only detected by a urine test. Either way, blood in the urine combined with flank or pelvic pain strongly points toward a stone.
You may also notice increased urgency, needing to urinate more frequently, or a burning sensation when you go, especially once the stone reaches the lower urinary tract. Cloudy or foul-smelling urine can develop if a bacterial infection sets in alongside the stone.
How It Differs From a UTI
Since kidney stones and urinary tract infections share symptoms like frequent urination and discomfort, many women initially assume they have a UTI. A few differences help separate them. UTI pain in women typically centers in the lower abdomen near the pubic bone and causes a burning sensation during urination. Kidney stone pain is usually higher up, in the back or side of the lower torso, and feels sharper and more stabbing. Visible blood in the urine is more common with stones than with a straightforward UTI.
The two conditions can also occur together. A stone that blocks the ureter traps waste products behind it, creating a breeding ground for bacteria. When that happens, you may develop fever, chills, and the cloudy urine typical of an infection on top of the stone symptoms.
Why It’s Easy to Mistake for a Gynecological Problem
Lower ureteral stones can produce pain deep in the pelvis or the labia, which closely mimics ovarian cysts, ovarian torsion, or severe menstrual cramps. Case reports in the urology literature document ovarian torsion being initially misdiagnosed as a kidney stone, and the reverse happens too. Calcifications visible on a basic X-ray can belong to either a ureteral stone or an ovarian mass, making imaging alone sometimes ambiguous.
If your pain is one-sided, came on suddenly, and is accompanied by blood in the urine or nausea, a kidney stone is more likely. If the pain correlates with your menstrual cycle or is accompanied by bloating and changes in bowel habits but no urinary blood, a gynecological cause is worth investigating. In practice, a CT scan reliably distinguishes between these possibilities.
When Symptoms Turn Serious
Most kidney stones are painful but not dangerous. However, a stone that fully blocks the ureter can lead to a kidney infection, which requires prompt treatment. Seek urgent care if you experience:
- Fever, chills, or sweating alongside flank pain, which suggests infection behind a blockage
- Persistent vomiting that prevents you from keeping fluids down
- Severe pain that doesn’t respond to over-the-counter painkillers
- Feeling very weak or tired with cloudy, bad-smelling urine
A blocked, infected kidney can deteriorate quickly, so these symptoms shouldn’t wait for a scheduled appointment.
How Kidney Stones Are Diagnosed
A non-contrast CT scan is the gold standard, with a sensitivity of 98% and specificity of 97% for detecting stones. For women with a BMI of 30 or below, a low-dose CT version reduces radiation exposure while keeping accuracy above 90%. This scan also rules out other causes of acute abdominal pain, including appendicitis and ovarian torsion.
Urinalysis plays a supporting role. Microscopic blood in the urine raises suspicion, but it isn’t specific to stones since infections and other kidney conditions can also cause it. The combination of imaging and urine testing gives the clearest picture.
If You’re Pregnant
Kidney stones during pregnancy present the same symptoms: flank pain (reported in 89 to 100% of pregnant women with stones), blood in the urine, and nausea. Stones can also trigger uterine contractions or mimic preterm labor. Ultrasound is the first-line imaging choice because it avoids radiation entirely. If ultrasound is inconclusive and symptoms persist, MRI without contrast is preferred in the first trimester. In the second and third trimesters, low-dose CT is an option when needed. The radiation from a low-dose CT falls well below the threshold associated with fetal harm.
Will the Stone Pass on Its Own?
That depends almost entirely on size. Studies tracking stones over 20 weeks found clear cutoffs:
- Under 3.5 mm: 98% pass without intervention
- 3.5 to 4.4 mm: 81% pass on their own
- 4.5 to 5.4 mm: 65% pass on their own
- 5.5 to 6.4 mm: 33% pass on their own
- 6.5 mm or larger: only 9% pass spontaneously
For smaller stones, your doctor will likely recommend drinking plenty of water and managing pain while the stone works its way out, a process that can take days to several weeks. Larger stones often require a procedure to break them up or remove them.
Who’s at Risk
Kidney stone rates in women have been climbing. Among women 65 and older on Medicare, prevalence rose from 2.1% to 3.1% between 2012 and 2021. Among women 18 and older on Medicaid, rates are comparable to men’s. Kidney stones frequently co-occur with obesity, high blood pressure, diabetes, and urinary tract infections. In adults under 65 with stones, 44% have hypertension, 32% have obesity, and 18% have diabetes. These conditions alter urine composition and metabolism in ways that promote crystal formation.
Recurrent UTIs are a particularly notable risk factor for women. In those 65 and older with kidney stones, 36% also had UTIs. Infections can change the chemistry of urine and create the conditions for certain types of stones to form, which is one reason women with frequent UTIs should mention any new flank or pelvic pain to their provider.