What is the normal activated partial thromboplastin time (aPTT) range?

The normal activated partial thromboplastin time (aPTT) range is typically between 25 to 35 seconds, but values can sometimes be cited as slightly higher, around 30-40 seconds, depending on the laboratory standards. This test is crucial because it evaluates the intrinsic and common pathways of coagulation and is commonly used to monitor patients on anticoagulants like heparin.

An aPTT value within the normal range suggests that the clotting factors are functioning properly, which is vital for normal hemostasis. If the aPTT is prolonged, it could indicate the presence of a bleeding disorder, the use of anticoagulant therapy, or other medical issues affecting blood coagulation. Understanding this range helps clarify patient management in situations involving anticoagulation therapy or preoperative assessments.