Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose National Hormone and Pituitary Program (NHPP): Information for People Treated with Pituitary Human Growth Hormone (Comprehensive Report) ?
    ### Response:
    CJD is usually diagnosed based on signs and symptoms of the illness, how severe they are, and how quickly they become worse. However, doctors must study brain tissue from a biopsy or autopsy in order to make a definite diagnosis of CJD.
                
Other tests can suggest CJD.
    