MEASURES THE TIME IT TAKES YOUR BLOOD TO CLOT, ALSO THIS TEST IS USED TO CHECK FOR BLEEDING PROBLEMS. PTT TEST IS USED TO EVALUATE THE ABILITY OF YOUR BLOOD TO CLOT. IF IT TAKES ABNORMALLY LONG TIME FOR THE BLOOD TO CLOT, IT CAN INDICATE A PROBLEM; THIS MAY BE A SIGN OF, DEFICIENT, OR DEFECTIVE CLOTTING FACTOR OR FACTORS; LIVER DISEASE; TREATMENT WITH HEPARIN (BLOOD THINNING DRUG). A CLOT IS A THICK LUMP OF BLOOD THAT THE BODY PRODUCES TO SEAL LEAKS, WOUNDS, CUTS, AND SCRATCHES, THIS PREVENTS EXCESSIVE BLEEDING