From the Guidelines
Hematuria, or blood in the urine, can result from various conditions affecting the urinary tract, including urinary tract infections, kidney stones, enlarged prostate in men, kidney disease, bladder or kidney cancer, certain medications, strenuous exercise, and trauma to the kidneys or bladder. The causes of hematuria can be divided into nephrogenic and urogenic causes, with renal parenchymal disease being the most common benign nephrogenic cause, and urolithiasis, infection, and benign prostatic hypertrophy being common benign urogenic causes 1. Malignant causes can occur anywhere in the urinary tract and are the main entity that must be excluded during the imaging evaluation of hematuria.
Common Causes of Hematuria
- Urinary tract infections (UTIs)
- Kidney stones
- Enlarged prostate in men
- Kidney disease
- Bladder or kidney cancer
- Certain medications (like blood thinners such as warfarin or aspirin)
- Strenuous exercise
- Trauma to the kidneys or bladder Gross hematuria has a high association with malignancy, with a risk of up to 30% to 40%, and therefore all patients with gross hematuria should have a full urologic workup 1. On the other hand, patients with microhematuria have a low risk of malignancy, ranging from 2.6% to 4% 1.
Evaluation and Management
Any instance of hematuria warrants medical evaluation, especially if persistent or accompanied by pain, as early detection of serious conditions like cancer improves treatment outcomes. Diagnostic workup usually includes urinalysis, imaging studies like CT scans or ultrasounds, and possibly cystoscopy to directly visualize the bladder. The treatment depends entirely on the underlying cause, ranging from antibiotics for infections to surgery for tumors or stones. Clinicians should consider urology referral for cystoscopy and imaging in adults with microscopically confirmed hematuria in the absence of some demonstrable benign cause 1.
From the Research
Causes of Hematuria
The causes of hematuria can be varied and range from benign conditions to serious diseases. Some of the potential causes of hematuria include:
- Infection, such as urinary tract infection 2, 3, 4
- Kidney stones or urolithiasis 2, 3, 5
- Trauma 2
- Exercise or spurious causes, such as foods, drugs or menstruation 2
- Tumors, including urological tumors and bladder cancer 2, 6, 3, 5, 4
- Benign prostatic enlargement 5
Urological Causes
Common urological causes of hematuria include:
Investigation and Diagnosis
Investigations for hematuria may include: