What does "hematuria" mean and what causes it?

Hematuria means blood in the urine, from hemato meaning blood and uria meaning urine condition. Gross hematuria is visible to the naked eye, while microscopic hematuria is detected only by laboratory testing. Common causes include urinary tract infections, kidney stones, bladder or kidney cancer, glomerulonephritis, trauma, and strenuous exercise. Even a single episode of gross hematuria requires investigation because it may be the first sign of urological malignancy.