What causes hematuria in men?

Causes of Hematuria in Men

Hematuria in men is most commonly caused by benign prostatic hyperplasia (BPH), urinary tract infections, and urolithiasis, but malignancy must be aggressively excluded—particularly in men over 35 years with gross hematuria, where cancer risk reaches 30-40%. 1, 2

Urologic Causes (Most Common in Men)

Benign Causes

• Benign Prostatic Hyperplasia (BPH): The most common benign urologic cause of hematuria specifically in men, particularly those over 50 years old 1, 2, 3
• Urinary Tract Infection: Common cause of both microscopic and macroscopic hematuria, presenting with pyuria and bacteriuria 1, 2, 4
• Urolithiasis: Kidney and ureteric stones typically cause painful hematuria with flank pain 1, 2, 4
• Trauma: Direct injury to kidneys or lower urinary tract 1, 2

Malignant Causes (Critical to Exclude)

• Bladder Cancer: Most frequently diagnosed malignancy in hematuria cases 2, 4
• Renal Cell Carcinoma: Upper tract malignancy 1, 2
• Prostate Cancer: Can produce lower urinary tract symptoms and hematuria 1

The risk of malignancy is dramatically higher with gross hematuria (30-40%) compared to microscopic hematuria (2.6-4%), making urgent urologic evaluation mandatory for any visible blood. 1, 2

Renal/Glomerular Causes

Primary Glomerular Disease

• IgA Nephropathy (Berger Disease): Most common glomerular cause of persistent isolated microscopic hematuria 3, 4
• Post-infectious Glomerulonephritis: Following streptococcal infection 2, 4
• Alport Syndrome: Hereditary nephritis with associated hearing loss and ocular abnormalities 2, 3, 4
• Thin Basement Membrane Nephropathy: Autosomal dominant condition, usually benign course 3, 4

Glomerular bleeding is suggested by tea-colored urine, proteinuria, red blood cell casts, and >80% dysmorphic RBCs on microscopy. 2, 4

Risk Stratification for Men

High-Risk Features Requiring Aggressive Workup

• Age ≥60 years: High risk category 2
• Smoking history >30 pack-years: High risk 2
• Gross hematuria: 30-40% malignancy risk regardless of other factors 1, 2
• Occupational exposure to chemicals/dyes: Increased bladder cancer risk 1, 2
• History of pelvic irradiation or cyclophosphamide exposure: Known carcinogenic risk 1

Intermediate-Risk Features

• Age 40-59 years: Intermediate risk 2
• Smoking history 10-30 pack-years: Intermediate risk 2
• Irritative voiding symptoms: May indicate bladder carcinoma in situ 1

Critical Clinical Pitfalls to Avoid

Anticoagulation therapy does NOT explain hematuria and should never delay full urologic evaluation—anticoagulants merely unmask underlying pathology. 1, 2, 4

Even transient or self-limited gross hematuria requires complete urologic workup, as intermittent bleeding is common with serious pathology including cancer. 2, 4, 5

In men with suspected BPH causing hematuria, digital rectal examination should be performed, and PSA measurement offered to those with ≥10-year life expectancy to exclude prostate cancer as a concurrent diagnosis. 1

Diagnostic Approach Algorithm

Step 1: Confirm True Hematuria

• Dipstick positivity must be confirmed with microscopic urinalysis showing ≥3 RBCs per high-power field 2, 4
• Exclude false positives from myoglobinuria, hemoglobinuria, or menstrual contamination 2

Step 2: Identify Benign Transient Causes

• Urine culture to confirm/exclude UTI (preferably before antibiotics) 1, 2
• Recent vigorous exercise history 1, 2
• Recent urologic instrumentation 1

Step 3: Determine Glomerular vs. Non-Glomerular Source

• Glomerular indicators: Dysmorphic RBCs >80%, RBC casts, significant proteinuria, tea-colored urine 2, 3, 4
• Non-glomerular indicators: Normal RBCs >80%, absence of proteinuria or casts 2, 3

Step 4: Risk-Stratified Urologic Evaluation

• Gross hematuria or high-risk microscopic hematuria: Urgent urology referral for cystoscopy and CT urography 1, 2, 6
• Intermediate-risk microscopic hematuria: Urology referral for cystoscopy and imaging 2, 7
• Low-risk microscopic hematuria with identified benign cause: May defer extensive imaging but maintain surveillance 1, 2

Step 5: Nephrology Evaluation When Indicated

• Concurrent nephrology referral if glomerular bleeding suspected, proteinuria present, elevated creatinine, or hypertension develops 2, 3, 7

For men over 50 with asymptomatic microscopic hematuria and no identified benign cause, serious underlying pathology including cancer must be ruled out aggressively, as the degree of hematuria does not correlate with severity of disease. 5, 7