ahealthyme - Everything to live a healthier life
Menu
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings Featured Tools
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Click a letter to see a list of medical procedures beginning with that letter.
Click 'Back to Intro' to return to the beginning of this section.

Thrombin Time

Does this test have other names?

Thrombin clotting time, TCT

What is this test?

Thrombin time is one of several tests that check if your blood is clotting normally. Blood clotting (coagulation) is needed to help stop bleeding when you have an injury.

Proteins in the blood called clotting factors help blood become sticky and lump together to stop bleeding. Thrombin is an enzyme in the liquid part of blood (plasma). It helps a clotting factor called fibrinogen turn into fibrin to create clots.
Thrombin time is a measure of how long the blood's plasma takes to form a clot. This test shows how long it takes fibrinogen to turn into fibrin. Problems with fibrinogen turning into fibrin can keep blood from clotting normally and cause too much bleeding.
The test may be used to help diagnose problems such as:

  • Inherited conditions that lead to low fibrinogen or fibrinogen disorders

  • Liver diseases such as cirrhosis, hepatitis, and liver cancer

  • Cancers such as kidney cancer (renal carcinoma) or multiple myeloma

  • Certain other health conditions, including lupus and ulcerative colitis

  • Antibodies against fibrinogen your body may be making, if you had surgery that uses fibrin glue from cow sources

  • Disseminated intravascular coagulation, a condition in which your body uses more fibrinogen

Some medicines can also lead to a longer thrombin time. This include these blood-thinning medicines:

  • Heparin

  • Warfarin

  • Hirudin

  • Bivalirudin

  • Argatroban

Why do I need this test?

You may need this test if your blood does not seem to be clotting normally.

Symptoms can include:

  • Excessive bleeding or bruising

  • Pregnancy problems, such as repeated miscarriages early in pregnancy, and abnormal bleeding after delivery

What other tests might I have along with this test?

You may need other tests to measure your blood's clotting ability. These include:

  • Reptilase time. Like thrombin time, this test measures how long it takes for fibrinogen to turn into fibrin. It shows if a long thrombin time is because of heparin.

  • Prothrombin time. This test gives information about fibrinogen and other blood parts that help form clots. It's also used to measure the effects of warfarin.

  • Activated partial thromboplastin time. This test also gives information about factors in blood clotting. And it is used to measure the effects of heparin.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider. 

The lab technician places thrombin from humans or cows in your plasma sample and records the number of seconds needed for it to form a clot. A normal thrombin time is about 14 to 19 seconds.

A longer thrombin time can mean low fibrinogen, high fibrinogen, or fibrinogen that's not working normally. It can also be because of medicines that affect blood clotting, such as heparin, argatroban, hirudin, or hirulog. 

A longer thrombin time can be caused by proteins in the blood from multiple myeloma or amyloidosis. Or it could be caused by antibodies to cow thrombin. 

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. The sample is placed in a tube containing a chemical that keeps it from clotting.

Does this test pose any risks?

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.

What might affect my test results?

Some medicines that alter blood clotting will affect your test results, such as heparin and warfarin.

How do I get ready for this test?

Tell your healthcare provider if you're taking any medicines, especially those that affect your blood's ability to clot. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don’t need a prescription and any illegal drugs you may use.  

Online Medical Reviewer: Fetterman, Anne, RN, BSN
Online Medical Reviewer: Haldeman-Englert, Chad, MD
Date Last Reviewed: 6/1/2018
© 2000-2018 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Featured Tools

For Blue Cross Blue Shield of Massachusetts members

Follow Us
Are you interested in becoming a member? Visit GetBlueMA   or call 1-800-422-3545.