Main content Tests for Erection Problems

    Tests for Erection Problems



    Results

    Tests for erection problems can help find a cause for a man's problem in having or maintaining an erection (Reference erectile dysfunction Opens New Window, or impotence).

    Tests for erection problems may include blood tests for testosterone, luteinizing hormone, prolactin, and thyroid hormone. A urine test, complete blood count, blood sugar level, and cholesterol and triglyceride levels may also be done.

    For more information on the lab tests done for erection problems, see the topics Reference Testosterone, Reference Prolactin, Reference Follicle-Stimulating Hormone, Reference Luteinizing Hormone, Reference Thyroid Hormone Tests, Reference Urine Test, Reference Complete Blood Count (CBC), Reference Blood Glucose, and Reference Cholesterol and Triglycerides Tests.

    Nocturnal penile tumescence (NPT) test

    An erection has likely occurred if:

    • One or more films on the snap gauge have broken.
    • The electronic device has recorded an increase in penis size.

    An erection has likely not occurred if:

    • None of the films on the snap gauge have broken.
    • The electronic device has not recorded an increase in penis size.

    The test is more accurate if repeat tests show the same results.

    Intracavernosal injection test

    An erection caused by intracavernosal injection is usually measured on a scale of 0 to 4, with a full erection measuring a 4.

    • If the test causes an erection with a value of 3 or 4, it is likely that your erection problems do not have a physical cause.
    • If the test causes an erection with a value of 0 to 2, your erection problems may have a physical cause.

    Doppler ultrasound

    The ultrasound can show if you have blood flow problems as the cause of your erection problems.



    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.