Find a Provider
From well-child visits to specialized treatment of complex illnesses and injuries, we offer comprehensive care from an exceptional team of doctors, nurses and allied professionals.
- Home
- Parents Home
- Allergy Center
- Asthma Center
- Cancer Center
- Diabetes Center
- A to Z Dictionary
- Emotions & Behavior
- First Aid & Safety
- Food Allergy Center
- General Health
- Growth & Development
- Flu Center
- Heart Health
- Homework Help Center
- Infections
- Diseases & Conditions
- Nutrition & Fitness Center
- Play & Learn Center
- School & Family Life
- Pregnancy Center
- Newborn Center
- Q&A
- Recipes
- Sports Medicine Center
- Doctors & Hospitals
- Videos
- Para Padres
- Home
- Kids Home
- Asthma Center
- Cancer Center
- Movies & More
- Diabetes Center
- Getting Help
- Feelings
- Puberty & Growing Up
- Health Problems of Grown-Ups
- Health Problems
- Homework Center
- How the Body Works
- Illnesses & Injuries
- Nutrition & Fitness Center
- Recipes & Cooking
- Staying Healthy
- Stay Safe Center
- Relax & Unwind Center
- Q&A
- Heart Center
- Videos
- Staying Safe
- Kids' Medical Dictionary
- Para Niños
- Home
- Teens Home
- Asthma Center
- Be Your Best Self Center
- Cancer Center
- Diabetes Center
- Diseases & Conditions
- Drugs & Alcohol
- Expert Answers (Q&A)
- Flu Center
- Homework Help Center
- Infections
- Managing Your Medical Care
- Managing Your Weight
- Nutrition & Fitness Center
- Recipes
- Safety & First Aid
- School & Work
- Sexual Health
- Sports Center
- Stress & Coping Center
- Videos
- Your Body
- Your Mind
- Para Adolescentes
Blood Test: Prothrombin Time (PT)
What Is a Blood Test?
By taking and testing a small sample of a person’s blood, doctors can check for many kinds of diseases and conditions. Blood tests help doctors check how the body’s organs are working and see if medical treatments are helpful.
To help your child get ready for a blood test, find out if they need to fast (not eat or drink) or should stop taking medicines before the test. Explain what to expect during the test. If your child is anxious about it, work together on ways to stay calm.
What Is a Prothrombin Time Test?
A prothrombin time (PT) test measures how long it takes for a clot to form in a blood sample. Clotting is important to help prevent too much bleeding. Proteins called clotting factors are needed for blood to clot properly. If there aren't enough of them, or any of them don't work as they should, it can take longer than normal for blood to clot.
Why Are PT Tests Done?
Doctors do PT tests to check for bleeding problems. A child might have the test if they’ve had a lot of bleeding or bruising, have a medical condition that can lead to problems with clotting, or are having surgery or a procedure that might cause bleeding. Doctors also do PT tests to follow clotting levels in children who are on blood-thinning medicines.
What if I Have Questions?
If you have questions about the PT test or what the test results mean, talk to your doctor.
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
© 1995- The Nemours Foundation. KidsHealth® is a registered trademark of The Nemours Foundation. All rights reserved.
Images sourced by The Nemours Foundation and Getty Images.