Below is an instruction from Human. Write a response.
    ### Instruction:
    What to do for Diagnosis of Diabetes and Prediabetes ?
    ### Response:
    - Tests used for diagnosing diabetes and prediabetes include the A1C testfor type 2 diabetes and prediabetesthe fasting plasma glucose (FPG) test, and the oral glucose tolerance test (OGTT). Another blood test, the random plasma glucose (RPG) test, is sometimes used to diagnose diabetes when symptoms are present during a regular health checkup.
    