About Occult Blood (Urine)
A positive dipstick blood test on urinalysis indicates haematuria (blood in the urine) or haemoglobinuria, and always requires follow-up to identify the cause. Even microscopic haematuria — blood invisible to the naked eye — warrants investigation for kidney stones, urinary tract infection, glomerulonephritis, or, in adults over 40, bladder cancer. A positive dipstick result should be confirmed with urine microscopy to determine whether actual red blood cells are present (versus free haemoglobin from haemolysis).