What is thrombocytopenia?

Thrombocytopenia (THROM-bo-sigh-toe-PEE-ne-ah) occurs when your blood platelet count is low. Platelets are also called thrombocytes. This type of blood cell clumps together to form blood clots to help stop bleeding at the site of a cut or wound. Another name for a blood clot is thrombus.

Bone marrow is the soft, spongy tissue inside bones that makes all blood cells including platelets. People who have thrombocytopenia don’t have enough platelets to form a blood clot. If you get a cut or other injury, you may bleed too much and the bleeding can be hard to stop.

Who might get thrombocytopenia?

Thrombocytopenia can affect people of all ages, races and genders. For unknown reasons, approximately 5% of pregnant women develop mild thrombocytopenia right before childbirth.

What are the types of thrombocytopenia?

The three main classes of thrombocytopenia are:

  • Platelet destruction such as with an auto-antibody that attaches to the platelet surface.
  • Platelet sequestration such as in someone with a large spleen or with liver disease.
  • Decreased platelet production as occurs in certain bone marrow diseases.

How common is thrombocytopenia?

It’s unknown how many people have thrombocytopenia. Many people have mild symptoms. They might not even know they have the condition. The autoimmune form of thrombocytopenia, immune thrombocytopenic purpura or ITP, affects approximately three to four out of every 100,000 adults and children.

Symptoms and Causes

What causes thrombocytopenia?

In rare instances, thrombocytopenia is inherited, or passed from parent to child. More commonly, certain disorders, conditions and medications cause a low platelet count. These include:

  • Alcohol use disorder and alcoholism.
  • Autoimmune disease which causes ITP. ITP is sometimes associated with other autoimmune conditions such as lupus.
  • Bone marrow diseases, including aplastic anemia, leukemia, certain lymphomas and myelodysplastic syndromes.
  • Cancer treatments like chemotherapy and radiation therapy.
  • Enlarged spleen caused by cirrhosis of the liver or Gaucher disease. The enlarged spleen traps platelets and other blood cells and prevents them from circulating in the blood stream.
  • Exposure to toxic chemicals, including arsenic, benzene and pesticides.
  • Medications to treat bacterial infections (antibiotics), seizures (epilepsy) and heart problems, or the blood thinner heparin.
  • Viruses, such as hepatitis C, CMV, EBV and HIV.

What are the symptoms of thrombocytopenia?

Some people with mild cases of thrombocytopenia don’t have symptoms. Often, one of the first signs is a cut or nosebleed that won’t stop bleeding. Other signs of low platelet count include:

Diagnosis and Tests

How is thrombocytopenia diagnosed?

If you have bleeding that’s difficult to stop or other signs of thrombocytopenia, your healthcare provider may do the following:

  • Physical exam: The healthcare provider will review your family history and medical history. You’ll discuss medications you take. Your healthcare provider will also check for bruises, rashes (petechiae) and an enlarged spleen or liver.
  • Blood count: A complete blood count (CBC) checks levels of platelets and white and red blood cells.
  • Blood clot test: A blood clot test measures the time it takes blood to clot. These tests include partial thromboplastin time (PTT) and prothrombin time (PT).

If your platelet count is low, your provider may order more tests to find the cause, such as:

  • Bone marrow biopsy: Taking a sample of bone marrow can help diagnose bone marrow diseases or cancer.
  • Imaging tests: Ultrasound or CT scan can check for an enlarged spleen, enlarged lymph nodes or liver cirrhosis.

Management and Treatment

How is thrombocytopenia managed or treated?

You might not need treatment if a low platelet count isn’t causing significant problems. Often, healthcare providers can improve platelet counts by treating the underlying cause. This approach may involve changing your medications.

Other treatments include:

  • Blood transfusion to temporarily increase platelet levels in your blood. Platelets are transfused only if the platelet count is extremely low. (Transfused platelets only last about three days in the circulation.)
  • Splenectomy or removal of the spleen.
  • Steroids (prednisone or dexamethasone), immunoglobulins (antibody proteins), and other medications that reduce platelet destruction and stimulate platelet production.

What are the complications of thrombocytopenia?

People with severe thrombocytopenia are at risk for significant internal and external blood loss, or hemorrhage. Internal bleeding into the digestive tract or brain (intercranial hemorrhage) can be life-threatening.

Having a splenectomy makes you more susceptible to infections. Your spleen is part of your immune system. It helps your body fight off germs. For this reason, patients who have to have their spleen remove are given several vaccinations to help prevent infection.


How can I prevent thrombocytopenia?

If you’re at risk for thrombocytopenia, these steps may help prevent it:

  • Avoid medicines that thin blood and increase bleeding risk, such as aspirin, naprosyn and ibuprofen.
  • Take care with contact sports and activities that can cause injuries, bruising and bleeding.
  • Minimize contact with toxic chemicals.
  • Take extra care when shaving, brushing your teeth and blowing your nose.
  • Limit your intake of alcohol which slows down the production of platelets and causes liver damage.

Outlook / Prognosis

What is the prognosis (outlook) for people with thrombocytopenia?

A low platelet count increases your risk of hemorrhage or severe bleeding. Excessive bleeding — whether internal or external — can be life-threatening. Many people with thrombocytopenia have mild to moderate symptoms. Platelet levels often go up when you treat the underlying cause or change medications.

Living With

When should I call my healthcare provider?

You should call your healthcare provider if you experience:

  • Blood in stool, urine or vomit.
  • Excessive bleeding or bleeding that won’t stop.
  • Extreme fatigue and weakness.
  • Nausea and vomiting.
  • Severe headaches.
  • Skin rash (petechiae).
  • Unexplained bruising.

What questions should I ask my healthcare provider?

You may want to ask your healthcare provider:

  • Why did I get thrombocytopenia?
  • What is the best treatment for me?
  • Are there any treatment risks or side effects?
  • What changes can I make to minimize bleeding and bruising?
  • Should I watch for signs of complications?

A note from Cleveland Clinic

If you have conditions that increase your risk for thrombocytopenia, it’s important to take precautions to protect your health. A low platelet count can put you at risk for excessive bleeding and bruising. Your healthcare provider can explain what’s causing the low platelet count and discuss treatment options. If your condition is severe, you may need to avoid activities that increase your risk of injury and bleeding.

Last reviewed by a Cleveland Clinic medical professional on 11/23/2020.


  • American Society of Clinical Oncology. ASCO Answers: Thrombocytopenia. ( Accessed 11/18/2021.
  • American Society of Clinical Oncology. Low Platelet Count or Thrombocytopenia. ( Accessed 11/18/2021.
  • Lupus Foundation of America. What Is Thrombocytopenia? ( Accessed 11/18/2021.
  • Medline Plus. Immune Thrombocytopenia. ( Accessed 11/18/2021.
  • Merck Manual. Overview of Thrombocytopenia. ( Accessed 11/18/2021.
  • National Heart, Lung, and Blood Institute. Thrombocytopenia. ( Accessed 11/18/2021.
  • National Organization for Rare Disorders. Immune Thrombocytopenia. ( Accessed 11/18/2021.

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