Partial thromboplastin time (PTT)
Alternate Names : APTT, PTT, Activated partial thromboplastin time
The normal value will vary between laboratories. In general, clotting should occur between 25 to 35 seconds. If the person is taking blood thinners, clotting takes up to two and a half times longer.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What do Abnormal Results Mean?
An abnormal (too long) PTT result may be due to: