From the Guidelines
Hematuria in women is most commonly caused by urinary tract infections, kidney stones, and benign prostatic hypertrophy, but can also be a sign of more serious conditions such as bladder or kidney cancer, particularly in older women or those with risk factors like smoking. According to the American College of Radiology 1, the causes of hematuria can arise from anywhere along the urinary tract and are generally divided into nephrogenic and urogenic causes. Renal parenchymal disease is the most common benign nephrogenic cause of hematuria, while common benign urogenic causes include urolithiasis, infection, and benign prostatic hypertrophy.
Some of the key factors associated with the development of a urinary malignancy include gross hematuria, age >35 years, smoking, occupational exposure to chemicals, and history of urologic disease 1. Gross hematuria has a high association with malignancy of up to 30% to 40%, and therefore all patients with gross hematuria should have a full urologic workup. On the other hand, patients with microhematuria have a low risk of malignancy ranging from 2.6% to 4%, and, in most patients with asymptomatic microhematuria, a cause is never found.
The evaluation of hematuria in women should include a thorough history, physical examination, urinalysis, and serologic testing prior to any initial imaging, as well as cystoscopy in many cases 1. Conditions specific to women, such as endometriosis involving the bladder and vaginal bleeding that mixes with urine, should also be considered. Any woman experiencing hematuria should seek medical evaluation promptly, as proper diagnosis requires urine tests, imaging studies, and possibly cystoscopy to visualize the bladder.
Key points to consider in the evaluation of hematuria in women include:
- Urinary tract infections and kidney stones are common causes of hematuria
- Benign prostatic hypertrophy is a common cause of hematuria in women, particularly in older women
- Gross hematuria has a high association with malignancy and requires a full urologic workup
- Microhematuria has a low risk of malignancy, but still requires evaluation to rule out serious conditions
- Conditions specific to women, such as endometriosis and vaginal bleeding, should be considered in the evaluation of hematuria.
From the Research
Causes of Hematuria in Women
The causes of hematuria in women can range from benign conditions to serious diseases. Some of the potential causes include:
- Urinary tract infection (UTI) 2
- Kidney stones
- Trauma
- Exercise or spurious causes, such as foods, drugs, or menstruation 3
- Tumors, including bladder, kidney, or prostate cancer 3, 4, 5
Classification and Investigation of Hematuria
Hematuria can be classified into visible and non-visible hematuria. The investigation of hematuria typically involves a series of tests and examinations to determine the underlying cause. These may include:
- Urine tests to check for blood, protein, and other abnormalities
- Imaging tests, such as ultrasound or CT scans, to visualize the kidneys and bladder
- Cystoscopy to examine the inside of the bladder and urethra
Risk Factors and Detection Rates
Certain factors can increase the risk of hematuria, including:
- Age: the risk of urological cancer increases with age 5
- Sex: men are more likely to develop urological cancer than women 2
- Smoking: cigarette smoking can increase the risk of urological cancer 5 The detection rates of urological cancer in patients with hematuria vary depending on the study, but it is estimated that around 20-25% of patients with visible hematuria and 5-10% of patients with non-visible hematuria will be diagnosed with a urological malignancy 4