The test is used to measure how many seconds your blood takes to form a clot. However, the standard normal level may vary with different labs, so it is better to consult your doctor to understand the results.
The normal value in a PTT is 60 to 70 seconds. But, this is an activated PTT (aPTT) test that measures blood clotting after adding a substance to your blood to make it clot faster. A typical APTT blood clotting time is 30 to 40 seconds.
If you get the test because you’re taking heparin, you’d want your PTT results to be more like 120 to 140 seconds, and your aPTT to be 60 to 80 seconds.
If your number is higher than normal, it may indicate that you are suffering from a bleeding disorder due to liver disease, haemophilia or others. If your number is lower than normal, that may be the reason for having several miscarriages in women.
If you have questions about your results, talk to your health care provider.