Erectile dysfunction, commonly called ED, is the persistent inability to get or maintain an erection firm enough for sex. It affects roughly 1 in 4 adult men in the United States, and while it becomes more common with age, it can occur at any point in adulthood. ED is not just a bedroom problem. It often signals underlying health issues, particularly involving the heart and blood vessels, that deserve attention.
How an Erection Works
An erection is a hydraulic event. When you become sexually aroused, your brain sends signals through nerves running along the spinal cord and into the pelvis. Those nerve signals trigger the smooth muscle tissue inside the penis to relax, which opens up the arteries and lets blood rush in. Spongy chambers called sinusoids expand with incoming blood, and as they swell, they compress the veins that would normally drain blood away. The result is a buildup of pressure that makes the penis rigid.
Any breakdown along this chain, from the brain signals to the nerve pathways to the blood vessels to the smooth muscle, can cause ED. That’s why the condition has so many possible causes.
Physical Causes
Most cases of ED have a physical component. The biggest category is vascular: anything that narrows arteries or limits blood flow can reduce the pressure needed for a firm erection. Atherosclerosis (the buildup of plaque inside artery walls) is the most common culprit, and it shares the same risk factors you’d associate with heart disease: high blood pressure, high cholesterol, diabetes, and smoking.
Diabetes deserves special mention because it damages both blood vessels and nerves. Diabetic nerve damage can dull the signals traveling from the brain to the penis, while elevated blood sugar stiffens artery walls over time. Chronic kidney disease, vascular disease, and low testosterone (defined by the American Urological Association as a total testosterone level below 300 ng/dL on two separate morning blood tests) can also contribute.
Nerve-related causes include spinal cord injuries, multiple sclerosis, stroke, and surgical damage. Operations on the prostate, bladder, or rectum can injure the small nerves that run close to those organs. Among men with complete upper spinal cord injuries, about 95% retain some reflex erection ability, but that drops to roughly 25% for those with complete lower cord injuries.
Psychological Causes
ED doesn’t always start with a physical problem. Performance anxiety is one of the most recognized psychological triggers. It creates a self-reinforcing cycle: worry about losing an erection makes you mentally monitor your own arousal (what sex researchers call the “spectator role”), which pulls you out of the moment and makes the erection harder to maintain. Each episode feeds more anxiety for the next one.
Depression is strongly linked to ED. In the Massachusetts Male Aging Study, men who reported depressive symptoms were nearly three times more likely to experience erectile problems, and those with a pessimistic outlook had almost four times the odds. Emotional stress and a history of sexual trauma also raise the risk significantly. Relationship conflict, low self-esteem, and general life stress round out the most common psychological contributors. In many men, psychological and physical factors overlap, each making the other worse.
How Common ED Is by Age
A 2021 national survey scored men using a standardized erectile function questionnaire and found an overall ED prevalence of 24.2%. The numbers climbed steadily with age: about 13% of men aged 25 to 44, 25% of those 45 to 54, 34% of men 55 to 64, 48% of men 65 to 74, and 52% of those 75 and older.
One striking finding was that 17.9% of men aged 18 to 24 also met the criteria, a rate higher than the 25 to 44 group. Researchers suspect performance anxiety, pornography habits, and psychological factors play a larger role in younger men. Perhaps the most important takeaway: only 7.7% of all men who qualified as having ED had ever been diagnosed by a healthcare provider, which points to a massive gap between how common the problem is and how rarely men bring it up.
ED as a Cardiovascular Warning Sign
The arteries supplying the penis are smaller than the ones feeding the heart, so they tend to show the effects of plaque buildup earlier. Research published in the American Heart Association’s journals found that ED can precede symptomatic cardiovascular disease by two to five years. That window matters. It means ED in a man with no known heart problems is a reason to check blood pressure, cholesterol, and blood sugar, not just a reason to ask for a prescription.
The American Urological Association’s current guidelines explicitly state that men should be counseled that ED is a risk marker for underlying cardiovascular disease and other health conditions that may warrant evaluation.
How ED Is Evaluated
Evaluation typically starts with a detailed medical, sexual, and psychosocial history. Your provider will want to know how long the problem has been going on, whether it happens in every situation or only certain ones (erections during sleep or morning erections that are still normal suggest a psychological rather than physical cause), and what medications you take.
A physical exam checks for signs of hormonal, neurological, or vascular issues. Blood work usually includes a morning testosterone level, along with tests for blood sugar, cholesterol, and kidney function. Validated questionnaires help grade severity on a standardized scale and track whether treatments are working over time. More specialized tests, like ultrasound of penile blood flow, are reserved for cases where the cause remains unclear or surgery is being considered.
Lifestyle Changes That Help
For men whose ED is related to weight, inactivity, or poor diet, lifestyle changes can produce real improvement, sometimes enough on their own. Losing just 5% to 10% of body weight in overweight or obese men has been shown to meaningfully improve erectile function. In one study of hypertensive men with ED, eight weeks of daily exercise lasting 45 to 60 minutes improved erections compared to a sedentary control group.
Current recommendations suggest at least 150 minutes per week of moderate aerobic activity. Combining exercise with medication appears to work better than medication alone. A diet rich in fruits (250 to 300 grams per day), vegetables, whole grains, nuts, and olive oil, essentially a Mediterranean-style pattern, has also been linked to better outcomes. Quitting smoking and reducing alcohol use round out the most evidence-backed changes.
Medications
Oral medications are the most common first-line treatment. They work by enhancing the natural signaling pathway that relaxes smooth muscle in the penis, making it easier for blood to flow in when you’re aroused. They do not create arousal on their own; sexual stimulation is still needed.
Sildenafil (Viagra) is taken about an hour before sex and lasts roughly four to six hours. Tadalafil (Cialis) works on a similar timeline but can last up to 36 hours, and a low daily dose is available for men who prefer not to plan around a pill. Both are available in a range of doses. Common side effects include headache, flushing, nasal congestion, and, less often, visual changes. These medications are not safe to combine with nitrate drugs used for chest pain, because the combination can cause a dangerous drop in blood pressure.
When Medications Don’t Work
If oral medications fail or aren’t tolerated, several other options exist. Vacuum erection devices use a pump to draw blood into the penis, then a constriction ring at the base holds it in place. They’re noninvasive and available without a prescription, though some men find them cumbersome.
Penile injections deliver medication directly into the erectile tissue, producing an erection within minutes regardless of arousal. They sound intimidating but use a very fine needle, and most men adapt quickly.
For men who don’t respond to any of these, a surgically implanted penile prosthesis is the most definitive solution. Inflatable models let you pump the device when you want an erection and deflate it afterward. Long-term data show a mechanical survival rate of about 93% at five years and 77% at ten years. Overall patient satisfaction sits near 87%, and 83% of recipients say they would choose the procedure again. Satisfaction with rigidity scores highest, at over 90%.
The Role of Testosterone
Low testosterone alone causes ED less often than many men assume, but it plays a supporting role. Testosterone fuels sex drive, and without adequate desire, the arousal signals that start the erection process may never fire strongly enough. When testosterone is genuinely low (below 300 ng/dL on repeated morning blood draws) and a man has symptoms like reduced libido, fatigue, or loss of muscle mass, replacement therapy can help restore sexual function. Testosterone on its own, however, rarely fixes ED that has a significant vascular cause. In those cases, it’s often combined with other treatments.