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

Hematuria—blood in the urine—can be visible (pink, red, or cola-colored urine) or microscopic (detected only by lab test). While often benign, it can signal serious conditions requiring prompt evaluation.

Common Causes

1. Urinary Tract Infection (UTI)

Bacterial infection of the bladder, urethra, ureters, or kidneys causes inflammation and bleeding. Often accompanied by burning urination, urgency, and frequency.

2. Kidney Disease

Glomerulonephritis, interstitial nephritis, and other kidney disorders damage filtering units, allowing red blood cells to leak into urine.

3. Urinary Stones

Kidney or bladder stones irritate and scratch the urinary tract lining, causing bleeding. Typically cause severe flank or abdominal pain.

4. Prostate Conditions (Men)

Benign prostatic hyperplasia (BPH) or prostate cancer can compress the urethra, leading to irritation and blood in urine.

5. Medications and Toxins

Anticoagulants (blood thinners), certain antibiotics, and exposure to heavy metals or chemicals can cause urinary bleeding or discoloration.

6. Trauma

Injury to the kidneys, ureters, or bladder from accidents, falls, or medical procedures.

7. Urethral Stricture

Narrowing of the urethra from scarring, infection, or inflammation obstructs flow and causes bleeding.

8. Cancer

Bladder, kidney, or ureteral cancers may present with painless hematuria. Risk increases with age and smoking history.

When to Seek Medical Care

Always consult a healthcare professional if you notice blood in your urine. Even if it resolves spontaneously, evaluation is needed to rule out serious underlying causes. Seek immediate care if accompanied by severe pain, inability to urinate, fever, or clots.