Erectile dysfunction may be the first manifestation of many diseases including diabetes mellitus, coronary artery disease, hyperlipidemia, hypertension, spinal-cord compression, pituitary tumors, and pelvic malignancies (Figure 1). The evaluation of a patient with ED requires a thorough history (medical, sexual and psycho-social), physical examination and appropriate laboratory tests (creatinine, fasting glucose, lipid profile, and testosterone) aimed at detecting these diseases. If the man's total testosterone concentration is low, serum free (or bioavailable) testosterone, prolactin, and lutenizing hormone should be further investigated.

After assessing the needs and goals of the patient and his partner, further diagnostic and treatment options should be contemplated. Consideration must be made of the patient's physical and mental health as well as his motivation and needs. The patient's performance status and cardiovascular health also need to be evaluated, if necessary in consultation with a cardiologist, in order to assess the patient's ability to tolerate sexual activity. Occasionally, a change in life-style or medications may be all that is needed to restore potency.

Some men may benefit from a referral for further testing and treatment (Table 2). The indications for specialty referral include: complex gonadal or other endocrine disorders, neurologic deficit suggestive of brain or spinal cord disease, deep-seated psychologic or psychiatric problems, Peyronie's disease, post-traumatic or primary erectile dysfunction, and active cardiovascular disease, especially if the patient wishes to take type 5 phosphodiesterase inhibitor.