Prothrombin time (PT) is a blood test. It measures how long it takes for blood to clot. Prothrombin is one of several clotting factors that the body makes. It helps your child's blood form clots when a blood vessel is damaged.
A PT test may also be called an INR (international normalized ratio) test.
Why is this test done?
The test can be used to check for bleeding problems. It is also used to check how well warfarin, a medicine to prevent blood clots, is working.
How do you prepare for the test?
In general, there's nothing you have to do before your child has this test, unless your doctor tells you to.
How is the test done?
A health professional uses a needle to take a blood sample, usually from the arm.
How long does the test take?
The test will take a few minutes.
What happens after the test?
Your child will likely be able to go home right away. And your child can go back to their usual activities right away.
Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor if your child is having problems. Ask your doctor when you can expect to have your child's test results.
Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.