Kidney stones are hard, solid masses formed from the crystallization of minerals and salts within the urinary tract, most often in the kidneys. These deposits can range from the size of a grain of sand to a pearl, causing intense pain when they move or block the flow of urine. Understanding the unique ways kidney stones affect women, from risk factors to symptom presentation, is important for accurate and timely diagnosis.
Kidney Stone Prevalence in Women
Historically, kidney stones were considered a condition predominantly affecting men, but recent epidemiological data show this gender gap is rapidly closing. While the overall prevalence rate in the United States remained relatively stable, the rate among women has risen significantly. Between 2007 and 2020, the prevalence of kidney stones in women increased from 6.5% to 9.1%, a notable shift compared to the stable rates observed in men.
This increase is particularly pronounced among younger women under the age of 60, suggesting a change in lifestyle or environmental factors over time. Although men still show a slightly higher lifetime risk, the accelerated rate of incidence in women means the perception of kidney stone disease as a primarily “male issue” is now outdated.
Factors That Increase Female Risk
Several physiological and anatomical differences contribute to a woman’s susceptibility to kidney stone formation. The shorter length of the female urethra makes women more prone to developing urinary tract infections (UTIs) than men. Recurrent infections can lead to the formation of struvite stones, which crystallize in response to chronic bacterial presence. Women are statistically more likely to have these infection-related struvite stones.
Hormonal changes throughout a woman’s life also play a significant role in altering the internal environment that prevents stone formation. Menopause, for instance, has been identified as a factor that increases the risk of stone disease. Additionally, the use of female hormone therapies may also contribute to a higher risk profile for some women.
Pregnancy introduces a complex set of changes that elevates the risk of developing a symptomatic kidney stone. Anatomical changes include ureteral compression from the growing uterus, which can lead to the dilation of the urinary tract and cause urine to slow or pool, a condition called urinary stasis. Physiologically, elevated levels of the hormone progesterone cause the ureters to relax, further contributing to this slowed flow.
The risk of a first-time symptomatic stone increases during the second and third trimesters of pregnancy. The risk peaks significantly in the period immediately following delivery, specifically within the first three months postpartum. Obesity has also been shown to be a stronger, disproportionate risk factor for stone formation in women compared to men.
Symptom Presentation and Misdiagnosis
The classic, severe pain associated with a kidney stone, known as renal colic, is experienced by both sexes, typically starting in the flank or side and moving downward. However, in women, the presentation of symptoms can often overlap with or be misattributed to gynecological conditions. This overlap frequently leads to a delay in diagnosis or misdiagnosis, as the pain may be mistaken for an ovarian cyst, endometriosis, or severe menstrual cramps.
The pain caused by a stone in the ureter may radiate to the lower abdomen, groin, or even the vulvar area, which closely mimics various gynecological or pelvic issues. Many women may also confuse the burning sensation during urination or the frequent urge to urinate with a simple urinary tract infection.
To achieve an accurate diagnosis, healthcare providers rely on imaging techniques such as CT scans and ultrasounds to visualize the stone’s size and location. Urinalysis is also performed to check for blood in the urine, known as hematuria, and signs of infection. Recognizing the potential for misdiagnosis is necessary toward ensuring women receive appropriate and timely treatment.