While anxiety sometimes causes erectile dysfunction, that disorder usually stems from physical problems, often the same ones that cause heart disease.

Sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) can help improve men's potency by dilating blood vessels in the penis, to allow for the increased blood flow necessary for an erection. However, such drugs should be used cautiously, since they can cause potentially serious side effects. Those risks may include an increased chance of heart attack or stroke among men already at risk of such events-including those with coronary disease-as well as fertility problems and worsened sleep apnea. In some men, the drugs may also cause temporary vision or hearing problems. And they can interact with many medications, most notably nitrates (used to relieve angina) and certain herbs, including St. John's wort.

What to do: Addressing coronary risk factors—reducing blood pressure, cholesterol levels, and weight, stopping smoking, exercising more, and rigorously treating diabetes—may help correct erectile dysfunction. Therapy or counseling might also help some people. Pelvic-muscle exercises called Kegels—where you tightly tense the muscles that interrupt the flow of urine or passage of gas—may be worth trying as well.

If reducing risk factors and performing Kegels don't help, men could consider erection-boosting medication. Tadalafil, which lasts for about 36 hours compared with 4 hours for the other two drugs, may be a good choice for men who value spontaneity, though side effects may also be prolonged. Men considering any impotence drug should first have a doctor assess their risk of heart disease and review all of their medications for possible interactions.