Erectile dysfunction (ED) is the inability to get or maintain an erection firm enough for sexual intercourse. It’s one of the most common sexual health issues men face, affecting roughly 1 in 4 men in the United States. While it becomes more common with age, it can happen at any stage of life, and it often signals something important about your overall health.
How Common ED Is by Age
A 2021 national survey published in The Journal of Sexual Medicine found an overall ED prevalence rate of 24.2% among U.S. men. The numbers shift substantially across age groups, but they may not follow the pattern you’d expect. About 17.9% of men aged 18 to 24 met diagnostic criteria, which was actually higher than the 13.3% rate in men aged 25 to 34 and the 12.7% rate in men aged 35 to 44. That early-life bump is largely driven by anxiety and inexperience rather than physical causes.
After 45, prevalence climbs steadily: 25.3% of men aged 45 to 54, 33.9% of those 55 to 64, 48% of those 65 to 74, and 52.2% of men 75 and older. The takeaway is that ED is extremely common, not a rare condition, and not something that only affects older men.
How an Erection Works
An erection is fundamentally a blood flow event. When you’re sexually aroused, nerve signals trigger the release of a chemical messenger called nitric oxide in the penile tissue. Nitric oxide causes the smooth muscle lining the blood vessels of the penis to relax and widen, allowing a rush of blood to fill the spongy tissue. That blood gets trapped under pressure, producing firmness. Anything that disrupts this chain, whether it’s nerve damage, restricted blood flow, hormonal shifts, or psychological interference, can cause ED.
Physical Causes
Most cases of ED in men over 40 have a physical component. The most common culprit is cardiovascular disease. The same process that narrows the arteries feeding your heart also narrows the smaller arteries supplying the penis. Because penile arteries are narrower than coronary arteries, they tend to show the effects of arterial damage first.
Diabetes is another major driver. Prolonged high blood sugar damages both the nerves that initiate erections and the blood vessels that supply them. High blood pressure and heart disease also contribute directly. Smoking narrows blood vessels and lowers your body’s production of nitric oxide, the key chemical that allows blood to flow into the penis. Being overweight independently worsens erectile function as well. Other physical causes include hormonal imbalances (particularly low testosterone), prostate surgery or radiation, spinal cord injuries, and certain medications like antidepressants and blood pressure drugs.
Psychological Causes
In younger men especially, the problem often starts in the mind rather than the body. Men under 30 are most likely to experience ED from nervousness and anxiety. Men over 30 tend to deal more with the weight of personal and professional stress. And men over 50 may face life transitions, like losing a partner or adjusting to retirement, that create emotional strain affecting sexual function.
Performance anxiety deserves special attention because it creates a self-reinforcing cycle. Worry about sexual performance triggers your body’s fight-or-flight response: your sympathetic nervous system activates, raising your heart rate and redirecting blood flow toward muscles you’d use to fight or run. That same response actively suppresses erections, because your body treats arousal as a non-essential function during perceived danger. One bad experience generates anxiety about the next attempt, which makes the next attempt more likely to fail, and the cycle deepens. This pattern can develop even in men with no underlying physical problem.
ED as a Cardiovascular Warning Sign
This is arguably the most important thing to know about ED: it can be an early warning sign of a heart attack or stroke. Because the first stage of arterial disease, endothelial dysfunction, typically affects the smaller penile arteries before it affects the larger coronary arteries, ED often shows up 3 to 5 years before a major cardiovascular event. That window is significant. It means an ED diagnosis gives you and your doctor time to check for and treat underlying arterial disease before it reaches your heart or brain. If you develop ED, particularly if it comes on gradually and you have risk factors like high blood pressure, high cholesterol, diabetes, or a smoking habit, a cardiovascular workup is worth pursuing.
How ED Is Evaluated
Doctors typically use a short validated questionnaire called the IIEF-5 (International Index of Erectile Function) to assess severity. It consists of five questions about your recent sexual experiences, scored on a combined scale. The severity categories break down as follows:
- Score 17 to 21: mild ED
- Score 12 to 16: mild to moderate ED
- Score 8 to 11: moderate ED
- Score 5 to 7: severe ED
Beyond the questionnaire, a doctor will often check blood pressure, blood sugar, cholesterol, and testosterone levels to identify contributing physical causes. The evaluation is straightforward and non-invasive.
Medication Treatment
The most widely used ED treatments are a class of oral medications that work by blocking an enzyme called PDE5, which normally breaks down the chemical that keeps penile blood vessels relaxed. By slowing that breakdown, these drugs help you maintain an erection once you’re aroused. They don’t create arousal on their own; sexual stimulation is still required.
The three main options differ primarily in how long they last. Sildenafil and vardenafil have similar durations, with a half-life of about 4 hours, meaning their useful window is roughly 4 to 6 hours after taking them. Tadalafil lasts much longer, with a half-life of about 17.5 hours in younger men and 21.5 hours in older men, which is why it’s sometimes called the “weekend pill.” All three can begin working in under 15 minutes for some men, though most people find the reliable window starts around 30 to 60 minutes after taking the pill. Fewer than 40% of men see results at the very earliest time points.
Tadalafil also comes in a low daily dose, which means you don’t have to plan around taking it before sex. Your doctor will help determine which option fits your lifestyle and health profile.
How Exercise Improves Erectile Function
Aerobic exercise is one of the most effective non-drug interventions for ED. A meta-analysis of 11 randomized controlled trials found that regular aerobic exercise improved erectile function scores by an average of 2.8 points on a standardized 30-point scale compared to controls. That improvement was clinically meaningful, particularly for men starting with worse function: men with severe ED saw improvements of about 4.9 points, moderate ED about 3.3 points, and mild ED about 2.3 points.
The mechanism is straightforward. Aerobic exercise improves blood vessel health, lowers blood pressure, reduces body fat, improves insulin sensitivity, and increases nitric oxide production. These are the same factors that, when impaired, cause ED in the first place. Walking, cycling, swimming, or jogging for 30 to 45 minutes several times per week is the general threshold where studies show benefit. Weight loss, when relevant, provides additional improvement by reducing inflammation and improving hormonal balance.
Other Treatment Approaches
When oral medications aren’t effective or can’t be used safely (particularly in men taking certain heart medications), other options exist. Vacuum erection devices use negative pressure to draw blood into the penis, with a constriction ring placed at the base to maintain the erection. Penile injections deliver medication directly into the tissue, producing an erection within 5 to 15 minutes regardless of arousal. For men with severe, treatment-resistant ED, surgical implants offer a permanent solution with high satisfaction rates.
When psychological factors are the primary cause, therapy focused on reducing performance anxiety and addressing relationship issues can be highly effective, sometimes on its own and sometimes alongside medication. For many men, the combination of lifestyle changes, addressing underlying health conditions, and short-term medication use resolves the problem without needing long-term treatment.