The platelet aggregation test is just one of a series of tests called a coagulation panel. Your doctor may order this test if he or she thinks you have a clotting problem.
What is a platelet aggregation test?
A platelet aggregation test is a blood test that looks at how well blood cells called platelets clump and clot. It is sometimes called a platelet function test
Platelets are important for inflammation, the immune system response, tissue growth, and controlling bleeding. When you get hurt in a way that breaks your skin, your body releases various chemicals that activate platelets and help stop the bleeding.
They stick to the lining of a blood vessel and clump together to make a plug that stops bleeding. A protein network forms around it and makes the plug stronger.
People sometimes have problems with platelets, which can be serious and life-threatening. This can include situations where the blood clots too much and causes a dangerous blockage, or where it doesn’t clot enough and you can’t stop the bleeding.
These can include:
- Von Willebrand disease
- Immune thrombocytopenia
- Preeclampsia, or high blood pressure in pregnancy
- Bernier-Soulier Syndrome
- Uremia, or high levels of urea in your blood
- Some medications
- Bone marrow disorders
Who should undergo a platelet aggregation test
Your doctor will order a platelet aggregation test if you have signs of bleeding, blood clots, or are at risk of heart disease.
Signs of thrombocytopenia include:
- Prolonged bleeding after a minor wound
- heavy or prolonged periods
- bleeding gums
- blood in urine
- blood in stool
- Unexplained bruising
- Small red spots on your skin called petechiae
- Purple spots on your skin
Signs of a blood clot include:
- Numbness in hands and legs
- Throbbing or cramping in your leg or arm
- Redness or swelling in your leg or arm
- breathing difficulties
- coughing up blood
You may have a platelet aggregation test if you are in the hospital or before surgery as part of routine patient testing.
Your doctor may also order this if you have a family member with an inherited platelet disease such as hemophilia, in which the blood does not clot.
Your doctor may use other routine blood tests in addition to the platelet aggregation test. This can include other blood clotting tests that look at the proteins on the platelets, how long it takes to clot, and the strength of the clot.
You may undergo a complete blood count called a CBC that looks at the number of red and white blood cells and platelets. A low platelet count may be a sign of another condition, such as cancer or kidney disease
The lipoprotein panel will test your cholesterol and triglyceride levels as well. This will show your risk of heart disease, which can affect blood clotting.
What to expect from a platelet aggregation test
A platelet aggregation test is a simple blood test. Your blood is drawn with a needle and sent to a laboratory. ?
The lab looks at how platelets circulate in the liquid part of blood, called plasma. They will add a chemical to the blood to see how the platelets clump together. If the blood sample remains cloudy after adding the chemical, it could be a sign of a problem with platelet clotting.
Platelet aggregation test results
Normal test results are temperature dependent and may vary between labs. A normal result means that your blood appears to clot normally
Abnormal results can mean that your platelets contain certain proteins or that they are not working properly. This could be a sign of an inherited platelet disease. ?
Certain medications or herbal supplements can alter your results. Your doctor may ask you to stop taking certain medications or supplements temporarily before the test
It can include:
- Antihistamines for allergies
- statins for cholesterol
- Non-steroidal anti-inflammatory drugs, or NSAIDs
- Blood thinners such as warfarin or aspirin
Be sure to discuss your medications with your doctor, but don’t stop taking anything unless your doctor tells you to.
Dangers of a platelet aggregation test
The risks of having blood drawn are very low. In most cases, you will feel a stinging and some discomfort, but it will pass quickly. Some people may bruise afterward
Some people experience other side effects in rare cases.
These can include:
- feeling faint
- heavy bleeding
If you are at risk of bleeding, you may need to be careful during the blood test. In general, the risks are low and can be an important test to find any problems. ?
Be sure to speak with your doctor if you feel unwell. If you have excessive bleeding or signs of a blood clot, this is a medical emergency and you should go to the hospital immediately.