Your doctor will diagnose immune thrombocytopenia (ITP) based on your medical history, a physical exam, and test results.
Your doctor will want to make sure that your low platelet count isn't due to another condition (such as an infection) or medicines you're taking (such as chemotherapy medicines or aspirin).
Your doctor may ask about:
During a physical exam, your doctor will look for signs of bleeding and infection. For example, your doctor may look for purplish areas on the skin or mucous membranes and pinpoint red spots on the skin. These are signs of bleeding under the skin.
You'll likely have blood tests to check your platelet count. These tests usually include:
You also may have a blood test to check for the antibodies (proteins) that attack platelets.
If blood tests show that your platelet count is low, your doctor may recommend more tests to confirm a diagnosis of ITP. For example, bone marrow tests can show whether your bone marrow is making enough platelets.
If you're at risk for HIV, hepatitis C, or H. pylori, your doctor may screen you for these infections, which might be linked to ITP.
Some people who have mild ITP have few or no signs of bleeding. They may be diagnosed only if a blood test done for another reason shows that they have low platelet counts.
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