En español | With all the advertisements you see on television for performance enhancing drugs for erectile dysfunction (ED,) you'd think every male on the planet had trouble rising to the occasion. Not so. Here's everything you need to know about this and other performance issues men encounter as they get older.

See also: How sex changes for men after 50.

1. ED is common, but not inevitable. Erectile Dysfunction is "the inability to achieve or maintain an erection sufficient for satisfactory sexual performance," according to the American Urological Association. Huh? If you're not sure what that means, that's because it's pretty vague. Simply put, ED means that a man who's sober (no alcohol or other erection-impairing drugs) cannot raise an erection during sex of any kind.

Turn your love life around by learning the facts about erectile dysfunction. — Photo by: Getty Images

Just how common is it? Landmark studies by University of Chicago researchers found that one third of men aged 50 to 64 suffer from ED. That figure jumps to approximately 44 percent for the 65 to 85 age group. So while ED is quite common in older men, more than half never develop it.

2. Some changes, however, are inevitable. Starting around age 50 (for some men, earlier), erections change — in some gradually, in others more quickly. Men lose the ability to raise erections solely from sexual fantasies. Direct fondling is necessary to raise them. When erections appear, they rise more slowly and are not as firm as they were when you first fumbled with condoms. And minor distractions, such as an ambulance siren, may cause wilting. These changes alarm many men, who jump to the conclusion that they must have ED. But if you can still raise an erection during masturbation, you don't. You have erection dissatisfaction.

Post-50 erection changes are normal and inevitable. But some lifestyle factors can postpone or even temporarily reverse them: falling madly in love, getting in shape and making love earlier in the day when you have more energy.

Unfortunately, other factors exacerbate erection dissatisfaction: anxiety, alcohol, many other drugs, relationship problems and making love when fatigued, i.e., late at night after a long day and a big dinner with wine.

Anxiety is particularly pernicious. It triggers the fight-or-flight reflex that sends blood away from the central body, including the penis, and out to the limbs for self-defense or escape. Less blood in the central body means less blood available for erection. Erection dissatisfaction is upsetting, but try to accept it. It's normal. If you become anxious, erections become less likely.

Good ways to minimize anxiety: a hot shower before sex and during lovemaking, deep meditative breathing, a slow pace and lots of sensual touch all over.

Next: Minimize your risk for ED. »