Causes of Hematuria (Technical explanation) for Medical Professionals
The causes of hematuria include urinary tract infection (UTI), urolithiasis, malignancies, benign prostatic hyperplasia (BPH), and nephropathies. 
- UTI: Microscopic hematuria is can be caused by UTIs. UTI is an infection that affects any part of the urinary tract. When it affects the lower urinary tract it is known as a simple cystitis (a bladder infection) and when it affects the upper urinary tract it is known as pyelonephritis (a kidney infection). Patients with UTIs generally have other voiding symptoms such as urinary burning and frequent urination.
- Urolithiasis: This is a condition in which urinary stones are formed or located anywhere in the urinary system. Smaller stones residing in the kidney may not cause pain or other symptoms and microscopic hematuria may be the only manifestation. Larger stones may also cause gross hematuria.
- Malignancies: Urological malignancies are potentially serious. Kidney cancer is often associated with microscopic hematuria and less often with gross hematuria unless advanced. Urothelial (bladder) cancer often presents with gross hematuria but can be found in patients with microscopic hematuria as well.
- BPH: Enlargement and growth of the prostate that happens as men age often causes constriction of the urethra. It commonly and progressively affects men as they age. Microscopic hematuria in men is a common symptom of BPH along with lower urinary tract obstructive or irritative symptoms.
- Nephropathies and Nephritis: Patients with nephropathies and nephritis often present with hematuria in addition to hypertension, edema, renal insufficiency, proteinuria, and urine RBC casts.