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What are Red Blood Cells in Urine?

Red blood cells (RBCs) in urine, known as hematuria, indicate the presence of blood that normally should not be there. This can result from issues anywhere along the urinary tract—from the kidneys to the urethra. Hematuria may be visible (gross hematuria), turning urine pink, red, or cola-colored, or microscopic, detectable only through laboratory testing. While some causes are benign, persistent hematuria requires medical evaluation to rule out serious conditions.

Understanding Red Blood Cells in Urine

Under normal circumstances, the kidneys filter waste from the blood while retaining blood cells. RBCs in urine signal that the urinary tract lining has been irritated or damaged, or that the kidney’s filtering units (glomeruli) are compromised.

Common Causes and Risk Factors

Urinary Tract Infections (UTIs)

  • Bacterial irritation of the bladder or urethra allows RBCs to leak into urine.
  • Often accompanied by burning during urination, urgency, and cloudy or odorous urine.

Kidney and Bladder Stones

  • Mineral deposits scrape urinary tract walls, causing bleeding.
  • May present with severe flank or abdominal pain.

Kidney Disease and Glomerulonephritis

  • Inflammation or damage to glomeruli allows RBCs into urine.
  • Can be related to autoimmune conditions, infections, or chronic disease.

Other Causes

  • Enlarged prostate (BPH) in older men
  • Strenuous exercise (“runner’s hematuria”)
  • Recent urologic procedures or catheter use
  • Certain medications (blood thinners, aspirin)
  • Inherited disorders (e.g., sickle cell disease, Alport syndrome)
  • Urinary tract cancers (bladder, kidney, prostate)

Diagnosis and Testing

  • Urinalysis: Detects and counts RBCs; normal urine has < 3 RBCs/high-power field.
  • Urine culture: Identifies infection-causing bacteria.
  • Urine cytology: Checks for abnormal or cancerous cells.
  • Blood tests: Evaluate kidney function (creatinine, BUN).
  • Imaging: Ultrasound, CT, or MRI to visualize kidneys, ureters, and bladder.
  • Cystoscopy: Endoscopic exam of the bladder and urethra.
  • Kidney biopsy: If glomerular disease is suspected.

Treatment Approaches

Treatment depends on the underlying cause:

  • UTIs: Antibiotics clear infection and resolve hematuria.
  • Kidney stones: Increased fluids, pain control, or procedures like lithotripsy.
  • BPH: Medications (alpha-blockers) or procedures to reduce prostate size.
  • Glomerulonephritis: May require corticosteroids, immunosuppressants, or blood pressure control.
  • Medication-related: Adjusting dose or switching drugs.

Lifestyle Support

  • Drink adequate fluids to dilute urine and flush the urinary tract.
  • Reduce high-oxalate foods if prone to stones.
  • Maintain healthy blood pressure.
  • Quit smoking to lower bladder cancer risk.
  • Use good hygiene to prevent UTIs.
  • Moderate intense exercise if it triggers hematuria.

When to Seek Medical Attention

See a healthcare provider promptly if you notice:

  • Visible blood in urine, even once
  • Blood with severe pain, fever, or inability to urinate
  • Blood clots in urine
  • Persistent microscopic hematuria, especially over age 40 or with cancer risk factors

Early evaluation can detect treatable conditions before they progress and improve long-term outcomes.

DISCLAIMER: ANY INSTANCE OF GROSS HEMATURIA OR PERSISTENT MICROSCOPIC HEMATURIA SHOULD BE EVALUATED BY A HEALTHCARE PROFESSIONAL.