Exams and Tests

Because both physical and psychological factors are often involved, it may be difficult to diagnose the exact cause of your erection problem.

As part of the initial evaluation, your health professional may:

• Review your risk factors for an erection problem. For more information, see the What Increases Your Risk section of this topic.
• Ask questions about your sexual function.
• Do a complete physical examination of the abdomen, penis, prostate, rectum, and testicles.
• Do laboratory tests for:
  • Testosterone. A low testosterone level may reduce sexual desire, leading to an erection problem.
  • Prolactin. A high level of prolactin (hyperprolactinemia) may indicate a small tumor in the brain, which can affect other hormone levels in the body. When hormone levels are affected, an erection problem may result.
  • Thyroid hormone. Either a high or low level of thyroid hormone may cause problems with sexual desire or erections.
  • Blood glucose. Elevated blood sugar (glucose) levels may indicate the presence of diabetes, which can contribute to erection problems.

At this point, oral medicines such as sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) are often recommended unless an easily treated cause (such as a medicine side effect or testosterone deficiency) has been identified. If oral medicines do not work or your doctor feels more testing is necessary, he or she may recommend:

• Specific tests for erection problems, such as a nocturnal penile tumescence testing (rigidity test) and an intracavernosal injection test. These both help determine whether physical or psychological factors are causing your erection problem.
• A psychological evaluation, if a psychological issue is suspected.

An ultrasound may be done if your doctor suspects you have a circulation problem (peripheral arterial disease). Even if the blood vessels cannot be repaired, it may be helpful to know if you have this condition because it may mean you have a risk for other blood vessel (vascular) problems. In very rare instances, you may have angiography—an X-ray test of blood flow through an artery. Its usefulness is limited because treatment to repair the blood vessels that supply blood to the penis is appropriate for very few men.