Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Zollinger-Ellison Syndrome ?
    ### Response:
    A health care provider diagnoses Zollinger-Ellison syndrome based on the following:
                
- medical history   - physical exam  - signs and symptoms  - blood tests  - upper gastrointestinal (GI) endoscopy  - imaging tests to look for gastrinomas  - measurement of stomach acid

    