Platelet Disorders

Also called: Thrombocyte disorders

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Summary

Platelets, also known as thrombocytes, are small pieces of blood cells. They form in your bone marrow, a sponge-like tissue in your bones. Platelets play a major role in blood clotting. Normally, when one of your blood vessels is injured, you start to bleed. Your platelets will clot (clump together) to plug the hole in the blood vessel and stop the bleeding. You can have different problems with your platelets:

If your blood has a low number of platelets, it is called thrombocytopenia. This can put you at risk for mild to serious bleeding. The bleeding could be external or internal. There can be various causes. If the problem is mild, you may not need treatment. For more serious cases, you may need medicines or blood or platelet transfusions.
If your blood has too many platelets, you may have a higher risk of blood clots.

When the cause is not known, this is called thrombocythemia. It is rare. You may not need treatment if there are no signs or symptoms. In other cases, people who have it may need treatment with medicines or procedures.
If another disease or condition is causing the high platelet count, it is thrombocytosis. The treatment and outlook for thrombocytosis depends on what is causing it.

Another possible problem is that your platelets do not work as they should. For example, in von Willebrand Disease, your platelets cannot stick together or cannot attach to blood vessel walls. This can cause excessive bleeding. There are different types of in von Willebrand Disease; treatment depends on which type you have.

NIH: National Heart, Lung, and Blood Institute

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Platelets (University of Oklahoma Health Sciences Center)

Diagnosis and Tests

Heparin-Induced Thrombocytopenia Antibody Test (American Association for Clinical Chemistry)
MPV Blood Test (National Library of Medicine) Also in Spanish
Platelet Function Tests (American Association for Clinical Chemistry)
von Willebrand Factor Test (American Association for Clinical Chemistry)
What Are Bone Marrow Tests? (National Heart, Lung, and Blood Institute)

Treatments and Therapies

Splenectomy (Mayo Foundation for Medical Education and Research) Also in Spanish
What Is a Blood Transfusion? (National Heart, Lung, and Blood Institute)

Specifics

Bernard-Soulier Syndrome (World Federation of Hemophilia)
Glanzmann Thrombasthenia (World Federation of Hemophilia) Also in Spanish
Heparin-Induced Thrombocytopenia (American Heart Association) - PDF
Idiopathic Thrombocytopenic Purpura (ITP) (Mayo Foundation for Medical Education and Research)
Immune Thrombocytopenia (National Heart, Lung, and Blood Institute)
Information about TTP-HUS (University of Oklahoma Health Sciences Center)
Petechiae (Mayo Foundation for Medical Education and Research) Also in Spanish
Storage Pool Deficiencies (World Federation of Hemophilia) Also in Spanish
Thrombocythemia and Thrombocytosis (National Heart, Lung, and Blood Institute)
Thrombocytopenia (National Heart, Lung, and Blood Institute)
Thrombocytosis (Mayo Foundation for Medical Education and Research)
Thrombotic Thrombocytopenic Purpura (National Heart, Lung, and Blood Institute)
von Willebrand Disease (National Heart, Lung, and Blood Institute)

Genetics

Genetics Home Reference: atypical hemolytic-uremic syndrome (National Library of Medicine)
Genetics Home Reference: Bernard-Soulier syndrome (National Library of Medicine)
Genetics Home Reference: dyserythropoietic anemia and thrombocytopenia (National Library of Medicine)
Genetics Home Reference: essential thrombocythemia (National Library of Medicine)
Genetics Home Reference: Glanzmann thrombasthenia (National Library of Medicine)
Genetics Home Reference: gray platelet syndrome (National Library of Medicine)
Genetics Home Reference: Hermansky-Pudlak syndrome (National Library of Medicine)
Genetics Home Reference: immune thrombocytopenia (National Library of Medicine)
Genetics Home Reference: Jacobsen syndrome (National Library of Medicine)
Genetics Home Reference: MYH9-related disorder (National Library of Medicine)
Genetics Home Reference: thrombotic thrombocytopenic purpura (National Library of Medicine)
Genetics Home Reference: von Willebrand disease (National Library of Medicine)
Genetics Home Reference: X-linked thrombocytopenia (National Library of Medicine)

Videos and Tutorials

Blood clotting (Medical Encyclopedia) Also in Spanish

Clinical Trials

ClinicalTrials.gov: Blood Platelet Disorders (National Institutes of Health)
ClinicalTrials.gov: Thrombocytopenia (National Institutes of Health)
ClinicalTrials.gov: von Willebrand Diseases (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

Find an Expert

Find a Hematologist (American Society of Hematology)
National Heart, Lung, and Blood Institute

Children

von Willebrand Disease (For Parents) (Nemours Foundation)

Teenagers

von Willebrand Disease (Nemours Foundation)

Patient Handouts

Bleeding time (Medical Encyclopedia) Also in Spanish
Congenital platelet function defects (Medical Encyclopedia) Also in Spanish
Glanzmann disease (Medical Encyclopedia) Also in Spanish
Idiopathic thrombocytopenic purpura (ITP) (Medical Encyclopedia) Also in Spanish
Partial thromboplastin time (PTT) (Medical Encyclopedia) Also in Spanish
Platelet aggregation test (Medical Encyclopedia) Also in Spanish
Primary thrombocythemia (Medical Encyclopedia) Also in Spanish
Purpura (Medical Encyclopedia) Also in Spanish
Thrombocytopenia (Medical Encyclopedia) Also in Spanish
Thromobocytopenia - drug-induced (Medical Encyclopedia) Also in Spanish