Final answer:
BT measures how long it takes for bleeding to stop, aPTT measures the time it takes for blood to clot, PT evaluates the extrinsic pathway of coagulation, and INR is a calculated ratio used to monitor and adjust warfarin dosage.
Step-by-step explanation:
BT (Bleeding Time):
BT is a test that measures how long it takes for bleeding to stop. It assesses the function of platelets and the blood vessel wall in hemostasis. A small incision is made on the skin, and the time it takes for bleeding to stop is recorded. Normal bleeding time is typically 2-9 minutes.
aPTT (Activated Partial Thromboplastin Time):
aPTT is a blood test that measures the time it takes for blood to clot. It evaluates the intrinsic pathway of coagulation. It is used to monitor the effectiveness of certain anticoagulant medications and to diagnose bleeding disorders. The normal range for aPTT is usually between 25-35 seconds.
PT (Prothrombin Time):
PT is a blood test that measures the time it takes for blood to clot. It primarily assesses the extrinsic pathway of coagulation. It is used to monitor the effectiveness of certain anticoagulant medications and to diagnose bleeding disorders. The results are typically reported as a ratio, called the International Normalized Ratio (INR). Normally, the PT is around 11-13 seconds, and an INR value of 1 is considered normal.
INR (International Normalized Ratio):
INR is a calculated ratio that helps standardize the PT results. It is used to monitor and adjust the dosage of the anticoagulant medication warfarin. A higher INR value indicates a longer time for blood to clot. The target INR range depends on the individual's condition, but generally, it falls between 2 and 3 for most indications.