Hematuria

Hematuria (blood in urine) can result from urinary tract infections, kidney or bladder stones, glomerulonephritis, trauma, vigorous exercise, benign prostatic enlargement, or cancers of the kidney, bladder, or prostate. Medications (anticoagulants) and inherited conditions (e.g., sickle cell, Alport syndrome) can also cause it. Investigation is important to find the underlying cause, especially if persistent, painless, or with other symptoms.

Treatment depends on the cause: evaluation with history, urine tests, imaging and cystoscopy guides therapy. For infections, antibiotics; for kidney or bladder stones, pain control and stone removal (lithotripsy or surgery); for tumors, surgery, chemotherapy or radiotherapy; for glomerular disease, immunosuppression and blood-pressure control; and stopping or adjusting anticoagulants when appropriate. Seek prompt medical assessment for significant or persistent bleeding.

The three commonly described types are: gross (macroscopic) hematuria — blood visible in the urine; microscopic hematuria — blood only detected by dipstick or microscope; and the clinical pain-based distinction (painless vs painful hematuria) used diagnostically (painless often raises concern for urinary tract malignancy, painful suggests stones or infection).

Red flags for hematuria include visible blood or clots, persistent or worsening bleeding, associated flank or suprapubic pain, fever or signs of infection, painful urination, reduced urine output, unexplained weight loss or night sweats, recent pelvic/abdominal trauma, anticoagulant use, and new-onset painless visible hematuria in older adults—especially if age over 45. Any of these require prompt medical assessment.

Several viruses can cause hematuria. Common causes include adenovirus (acute hemorrhagic cystitis, especially in children), BK virus (polyomavirus-associated nephropathy in transplant recipients), hantaviruses (hemorrhagic fever with renal involvement), hepatitis B and C (immune-complex glomerulonephritis), and cytomegalovirus in immunocompromised patients. Presentation and severity vary with the virus and host immune status, and may require specific testing and targeted treatment.

Yes — hematuria can sometimes resolve on its own or after treating the underlying cause (urinary tract infection, kidney stones, vigorous exercise, medications). However, blood in the urine can signal serious conditions (stones, kidney disease, bladder cancer) and needs evaluation if visible, persistent, or accompanied by pain, fever, or significant weight loss. Your clinician may order urine tests and imaging to determine cause and follow-up.