Blood in Urine (Hematuria): Causes, Symptoms, and When to See a Doctor

What Is Hematuria?

Hematuria is the presence of red blood cells in the urine. It can be gross (visible pink, red, or cola-colored urine) or microscopic (detected only by lab test). While often alarming, it is a symptom—not a disease—and requires medical evaluation to identify the underlying cause.

Common Causes

1. Urinary Tract Infection (UTI)

Bacterial infection of the bladder (cystitis) or kidneys (pyelonephritis). Symptoms: burning urination, urgency, frequency, cloudy/foul-smelling urine, fever, flank pain.

2. Kidney Stones

Hard mineral deposits that cause severe flank/abdominal pain, nausea, vomiting, and hematuria as they pass.

3. Prostate Conditions (in Men)

Benign prostatic hyperplasia (BPH) or prostatitis can cause difficulty urinating, frequency, and blood in urine.

4. Urinary Tract Cancers

Bladder, kidney, or prostate cancer may present with painless hematuria, weight loss, fatigue, or persistent flank pain.

5. Other Causes

• Trauma to the kidneys or bladder
• Strenuous exercise (exertional hematuria)
• Medications: blood thinners (warfarin, aspirin), certain antibiotics, chemotherapy
• Glomerulonephritis (kidney inflammation)
• Inherited disorders (e.g., sickle cell trait, Alport syndrome)
• Endometriosis (in women)

When to Seek Medical Attention

See a doctor promptly for any visible blood in urine. Even if it resolves, evaluation is needed to rule out serious conditions. Seek immediate care if accompanied by:

• Inability to urinate
• Severe flank or abdominal pain
• High fever and chills
• Passing blood clots

Diagnostic Approach

Typical workup includes urinalysis, urine culture, blood tests (creatinine, PSA in men), imaging (CT urogram or ultrasound), and possibly cystoscopy.