Platelet Tests
Reviewed
Also called: platelet count, PLT, PLT count, thrombocyte count, platelet function tests, PFT
There are two types of platelet tests: a platelet count test and platelet function tests. A platelet count test measures the number of platelets in your blood.
Specimen: blood sample
Why this test may be ordered
- To monitor or diagnose conditions that cause too much bleeding or clotting.
- As part of a complete blood count during a routine checkup.
- To help diagnose platelet diseases.
- To check platelet function during complex surgical procedures (e.g., coronary artery bypass surgery, trauma surgery).
- To evaluate patients before surgery if they have a personal or family history of bleeding disorders.
Preparation and collection
You don't need any special preparations for a platelet count test. If you are getting a platelet function test, you may need to stop taking certain medicines, such as aspirin and ibuprofen, before your test. Tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to.
Most platelet tests are done on a blood sample. During the test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Your provider may consider your symptoms, medical history, and the results of other blood tests to understand the results of your platelet tests.
What does a low platelet count mean?
Lower-than-normal platelet count (thrombocytopenia): If your results show a lower-than-normal platelet count (thrombocytopenia), it may be a sign of: A cancer that affects the blood, such as leukemia or lymphoma. A viral infection, such as mononucleosis, hepatitis, or measles. An autoimmune disease. Infection or damage to your bone marrow. Limitation: Gestational thrombocytopenia. A common, but mild, low-platelet condition that can occur during pregnancy. It is not known to cause any harm to the mother or fetus. Next step: Your provider may consider your symptoms, medical history, and the results of other blood tests to understand the results of your platelet tests.What does a high platelet count mean?
Higher-than-normal platelet count (thrombocytosis): If your results show a higher-than-normal platelet count (thrombocytosis), it may be a sign of: Certain types of cancer, such as lung cancer or breast cancer, Anemia, Inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, Rheumatoid arthritis, A viral or bacterial infection, Severe blood loss. Limitation: This can make your blood clot more than you need it to. Blood clots can be dangerous because they can block blood flow. Next step: Your provider may consider your symptoms, medical history, and the results of other blood tests to understand the results of your platelet tests.- Platelet function test not normal: If your platelet function test results were not normal, it may be a sign of an inherited or acquired platelet disorder. Limitation: If you are taking anti-platelet medicine, like aspirin, your results show how well your medicine is working. Next step: Your provider may consider your symptoms, medical history, and the results of other blood tests to understand the results of your platelet tests.
- The source does not provide specific reference ranges or units; results are interpreted by the healthcare provider.
- Platelet function tests may not be available at all locations; some specialized tests are only available at certain hospitals and laboratories.
- False positives or false negatives are possible; results must be interpreted in the context of symptoms, medical history, and other tests.
What to do next
Your provider may consider your symptoms, medical history, and the results of other blood tests to understand the results of your platelet tests.
- What are the symptoms that led to this test?
- Are you taking any medicines that affect blood clotting?
- Do you have a personal or family history of bleeding or clotting disorders?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.