Hematuria means blood in the urine. It can be due to inflammation, injury, or any other condition in an organ of the urinary system, the kidneys, ureters, bladder, urethra, and prostate in men. It's presence can not be seen with the naked eye and is discovered on a test strip, which comes in contact with the urine: this is called microscopic hematuria, as opposed to gross hematuria, when the color is visibly pink or red. In cases of discoloration, a strip test must be done because certain foods or medications can be responsible for false hematuria. Generally, when the urine is red only at the beginning of urination, the origin of hematuria is suspected to be lower down, affecting the urethra or the prostate in men. When urine is only red at the end of urination, an origin in the bladder is suspected. In cases of red urine throughout urination, any condition is possible, but the kidney is frequently involved. Kidney stones and urinary tract infections are the main causes of hematuria , a cancerous origin is also possible.