Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Essential Thrombocythemia ?
    ### Response:
    Patients with essential thrombocythemia may have no signs or symptoms. Essential thrombocythemia often does not cause early signs or symptoms. It may be found during a routine blood test. Signs and symptoms may be caused by essential thrombocytopenia or by other conditions.
    