Experiencing blood in urine, or hematuria, can be unsettling. While sexually transmitted infections (STIs) are a possible cause, many other conditions can also lead to this symptom. Hematuria indicates the presence of red blood cells in urine, ranging from visibly red or pink (gross hematuria) to microscopic amounts detectable only with lab tests. Identifying the cause requires medical evaluation.
Sexually Transmitted Infections and Blood in Urine
Certain sexually transmitted infections can lead to blood in the urine by causing inflammation or tissue damage in the urinary tract or surrounding reproductive organs. These infections often cause urethritis, an inflammation of the urethra (the tube carrying urine out of the body). When inflamed, small blood vessels can become irritated and rupture, leading to blood in the urine.
Chlamydia, a common bacterial STI, frequently causes urethritis. This inflammation can result in symptoms such as painful urination, an urgent need to urinate, and sometimes visible blood in the urine. Similarly, gonorrhea, another bacterial infection, can infect the urethra, leading to urethritis and associated bleeding and discomfort during urination. Both chlamydia and gonorrhea can also infect other areas, such as the cervix in women or the prostate in men, potentially contributing to urinary symptoms.
Herpes Simplex Virus (HSV), known for causing painful blisters and sores, can also cause urethritis. When HSV infects the urethra, it leads to inflammation and discomfort, potentially including blood in the urine. While lesions are typically external, their proximity to the urethral opening can contribute to urinary symptoms. Trichomoniasis, caused by a parasite, can also induce urethritis and vaginitis, leading to inflammation and irritation that may result in hematuria.
Common Non-STD Causes of Blood in Urine
Beyond STIs, many other conditions commonly cause blood in the urine. Urinary Tract Infections (UTIs) are among the most frequent non-STI causes, particularly in women. Bacteria entering the urinary tract inflame and irritate the lining of the urethra, bladder, or kidneys, leading to blood in the urine.
Kidney stones, hard mineral deposits forming in the kidneys or bladder, are another common cause. As these stones move through the urinary tract, they can scrape and irritate the lining, causing bleeding that ranges from microscopic to visibly red. Bladder or kidney infections (pyelonephritis), often a progression of untreated UTIs, also cause significant inflammation and can lead to blood in the urine, sometimes accompanied by fever and back pain.
Strenuous exercise, like long-distance running, can temporarily cause “exercise-induced hematuria.” The exact mechanism is not fully understood, but it may involve minor trauma or changes in kidney filtering during intense activity. Certain medications, such as blood thinners (e.g., warfarin, aspirin) or some antibiotics, can also cause hematuria by affecting blood clotting or irritating the kidneys. More serious conditions like kidney disease, including glomerulonephritis (inflammation of the kidney’s filtering units), or bladder and kidney cancers, can also manifest with blood in the urine.
Seeking Medical Evaluation for Blood in Urine
Any instance of blood in the urine, whether visible or microscopic, warrants prompt medical evaluation. While some causes are benign, hematuria can indicate a serious underlying condition. Ignoring this symptom could delay diagnosis and treatment.
A healthcare provider will typically begin with a thorough medical history, asking about symptoms, recent activities, and any medications. They will likely order a urine test (urinalysis) to confirm the presence of blood and check for signs of infection or other abnormalities. Depending on the initial findings, further tests might include blood work, imaging studies like ultrasounds or CT scans of the urinary tract, or a cystoscopy, which involves inserting a thin camera into the bladder to visualize its lining. Early and accurate diagnosis allows for appropriate treatment, addressing the specific cause of the hematuria, whether it’s an STI, a kidney stone, an infection, or another condition.