Why Platelet Count Matters

Platelets are a type of blood cell. They are involved in producing blood clots, which help stop bleeding from wounds. Your platelet count is an estimate of the concentration of platelets in your blood, and it is part of a routine complete blood count (CBC).

Certain diseases and medications can cause platelets to be too high or too low. An abnormal platelet count can cause health problems, such as excessive bleeding from wounds or a predisposition to blood clots.

This article explains what a normal platelet count is, what to expect if your platelet count is too high or too low, and how to treat abnormal platelet counts.

Platelet Count: What Do Ranges Mean?

Platelets are small blood cells that are made in the bone marrow, lasting for about 7 to 10 days. A healthy platelet count ranges from 150,000 to 400,000 per microliter. This generally means that your body is regenerating platelets at a steady rate to replace older platelets that normally disintegrate.

Low Platelet Ranges

A platelet count below 150,000 per microliter is considered low. A low platelet count is called thrombocytopenia. Several conditions and medical treatments can cause low platelets. 

Causes include:

• Anticoagulant medication, like heparin
• Other medications, including some antibiotics (sulfonamides, ampicillin, piperacillin, vancomycin, rifampin) and older anti-epileptic agents such as carbamazepine and phenytoin
• Bone marrow disease
• Blood cancers
• Chemotherapy
• Liver disease
• A severe infection, illness, or malnutrition
• Thrombotic thrombocytopenic purpura (TTP, a rare condition in which platelets clump and form clots in small blood vessels)

A low platelet count can increase the risk of bruises and gastrointestinal bleeding or may predispose to life-threatening bleeding (such as a hemorrhagic stroke).

Normal Platelet Ranges

A normal platelet range is between 150,000 and 400,000 per microliter. It is an indication that the rate of your platelet production is about equal to your normal platelet breakdown. Having a normal platelet count can allow your body to have a normal blood-clotting process, but platelets are only one component of that process.

High Platelet Ranges

A platelet count above 450,000 per microliter is considered high. You can have a high platelet count due to underlying disease—this is called secondary or reactive thrombocytosis.

Causes of this type of thrombocytosis include inflammation, cancer, splenectomy (surgical removal of the spleen), anemia (low red blood cell function), and heart disease. Excessive platelet production may also be caused by a rare genetic condition.

Having a high platelet level can be a risk factor for harmful blood clots that can cause:

• Deep vein thrombosis (blood clot in a vein, usually in the leg)
• Pulmonary embolism (blood clot lodged in an artery in the lungs)
• Myocardial infarction (heart attack due to blocked blood vessels that support the heart muscle)
• Stroke (blockage of blood flow to the brain)

Normal platelet count can vary based on age and sex.

Understanding Normal Platelet Function

Platelets are a key component of blood-clotting, which helps prevent excessive bleeding. These small blood cells are formed in the bone marrow and stored in the spleen. Typically, some platelets also flow through the blood vessels.

When you have a wound or injury superficially or inside the body, platelets adhere to the exposed matrix of injured blood vessels. The platelets are activated to secrete products that further stimulate the production of a platelet plug and blood clot.

With autoimmune thrombocytopenia, the immune system can lead to platelet destruction. The condition can develop in response to an infection, or sometimes without a cause. Autoimmune thrombocytopenia leads to a deficit in platelets, with prolonged bleeding after injuries, and even sometimes without a noticeable injury.

Treatment can include corticosteroids or other immune suppression, platelet stimulating medication, or a splenectomy.

Who Should Monitor Their Platelet Count

Normally, platelet count is measured with a standard CBC. For most people it’s recommended to have a standard CBC every year, along with the regular routine physical. If you have a condition that could cause any abnormality in blood cells, you might need to have more frequent CBC testing, along with platelet count.

You may need to have your platelets measured at specific intervals if you have a health condition that predisposes you to a high or low platelet count, such as thrombocytopenia or a history of cancer, or if you are taking medication that alters platelet levels.

How to Treat Low or High Platelet Count 

If your platelet count is too high or too low, you will need medical treatment. Usually, therapy for an abnormal platelet count involves medication, and possibly blood transfusions or other therapeutic interventions.

Treatments for high platelet count include:

• Management of the underlying cause (such as treatment for iron deficiency anemia)
• Angrylin (anagrelide), a medication that helps lower platelet count
• Hydria or Droxia (hydroxyurea), a medication that helps lower platelet count
• Plateletpheresis, which is physical removal of blood platelets through a vein

Treatments for low platelet count include:

• Management of the underlying cause
• Platelet transfusion (not indicated for some conditions, such as TTP)
• Medications to stimulate increased platelet production, such as Promacta (eltrombopag) and Nplate (romiplostim)
• Corticosteroids for immune-mediated thrombocytopenia
• Splenectomy
• For thrombotic thrombocytopenic purpura (TTP), plasmapheresis and plasma exchange (the liquid part of your blood containing abnormal proteins is removed and replaced with donor plasma)

Additionally, you may need to incorporate certain lifestyle changes to help manage problems with your platelet count.

Important at-home methods for managing abnormal platelet count include:

• Not smoking
• Only using blood thinners as directed by your healthcare provider
• Maintaining a healthy diet that includes necessary vitamins, minerals, and protein—and taking nutritional supplements as recommended by your healthcare provider

Next Steps After Abnormal PLT Blood Test 

If your blood test shows an abnormal platelet count, you should follow up with your healthcare provider. You may need additional tests to diagnose the underlying cause of your platelet dysfunction.

Other tests may include a blood smear (microscopic examination of a blood sample), X-rays, liver function tests, or a bone marrow biopsy. The next steps in your diagnostic testing would be determined by your underlying risk factors, whether your platelets are high or low, and whether any of your other blood measurements are abnormal.

Summary 

Platelets are an essential part of healthy healing. Your platelet count can be measured with a simple CBC blood test. Abnormalities in platelet count can cause serious health consequences and could also be indications of an underlying disease.

If you have an abnormally high or low platelet count, it’s important that you get diagnosed so that you can get started on appropriate treatment as soon as possible. Often, the platelet count can be corrected with treatment.

In some cases, you may need long-term treatment, as well as ongoing surveillance of your platelet count to assess whether the treatment is working effectively.