Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Thrombocythemia and Thrombocytosis ?
    ### Response:
    Thrombocythemia (THROM-bo-si-THE-me-ah) and thrombocytosis (THROM-bo-si-TO-sis) are conditions in which your blood has a higher than normal number of platelets (PLATE-lets).
                
Platelets are blood cell fragments. They're made in your bone marrow along with other kinds of blood cells.
    