Difficulty maintaining an erection is one of the most common sexual health issues men experience, and it rarely means what you might fear. Between 5% and 10% of men under 40 deal with it, and the rate climbs to about 22% by age 40. The causes range from stress and medication side effects to physical health issues, and most of them are treatable once identified.
How Erections Work (and Fail)
An erection depends on a specific chain of events. Sexual arousal triggers the release of a chemical messenger called nitric oxide, which relaxes the smooth muscle tissue inside the penis. That relaxation allows blood to rush in and fill the spongy tissue, while veins compress to trap the blood in place. If anything disrupts that chain, whether it’s a hormonal signal, a blood flow problem, or a nervous system response, the erection can weaken or disappear mid-act.
The key thing to understand is that erections aren’t purely about attraction or desire. They’re a vascular event controlled by the nervous system. Your boyfriend can be completely attracted to you and still lose his erection because something is interfering with the physical mechanics or the brain signals that sustain it.
Stress and Anxiety Are the Most Common Culprits
When the body perceives a threat, even a psychological one like worrying about sexual performance, it activates the fight-or-flight response. The sympathetic nervous system speeds up heart rate, deepens breathing, and shuts down functions the body considers nonessential in a crisis. Erections are one of the first things to go. This is a hardwired survival response, not something your boyfriend can think his way out of in the moment.
If stress is ongoing, whether from work, finances, relationship tension, or anything else, the body ramps up cortisol production. Chronically elevated cortisol suppresses testosterone, the hormone primarily responsible for sex drive. It also contributes to blood pressure changes that can make erections harder to maintain. So even background stress that has nothing to do with sex can show up in the bedroom.
Performance anxiety creates a particularly vicious cycle. He loses his erection once, then worries about it happening again, which triggers the exact stress response that caused the problem in the first place. Each episode reinforces the anxiety. This pattern is extremely common in younger men and can develop even after a single embarrassing experience.
Medications That Interfere
If your boyfriend takes any prescription medication, that’s worth looking into. Several common drug classes list erection problems as a frequent side effect.
- Antidepressants and anti-anxiety medications: SSRIs like fluoxetine (Prozac) and sertraline (Zoloft), along with benzodiazepines like diazepam (Valium) and lorazepam (Ativan), are well-known offenders.
- Blood pressure medications: Thiazide diuretics (water pills) are the most common cause of erection issues among blood pressure drugs, followed by beta blockers like atenolol and metoprolol.
- Antihistamines: Over-the-counter allergy and heartburn medications like diphenhydramine (Benadryl) and ranitidine can also contribute.
- Hair loss treatments: Finasteride (Propecia) is a known cause of sexual side effects in some men.
If a medication seems like the likely cause, he should talk to his prescriber about alternatives or dosage adjustments. Stopping a medication abruptly can be dangerous, but switching to a different drug in the same class often resolves the issue.
Lifestyle Factors That Add Up
Erections are essentially a test of cardiovascular fitness. Anything that impairs blood flow will eventually affect erectile function. Smoking is one of the biggest risk factors because nicotine damages blood vessel walls and restricts circulation. Being significantly overweight increases the risk regardless of exercise level, since excess body fat raises estrogen levels and promotes inflammation that impairs blood vessel function.
Exercise has a measurable protective effect. Research from Harvard found that men who ran for about 90 minutes per week were 20% less likely to develop erection problems than sedentary men. Those who ran two and a half hours a week saw a 30% reduction in risk. The benefits come from improved blood vessel health, better hormone balance, and lower stress hormones.
Sleep matters more than most people realize. Poor sleep, particularly from untreated sleep apnea, tanks testosterone levels and raises cortisol. Heavy alcohol use is another common factor. Alcohol is a central nervous system depressant that temporarily impairs the nerve signaling needed to maintain an erection, and chronic heavy drinking can cause lasting hormonal and vascular damage.
When It Signals Something Physical
Erection problems can be an early warning sign of cardiovascular disease. The arteries that supply the penis are only 1 to 2 millimeters wide, making them among the first blood vessels in the body to show signs of plaque buildup. In many cases, difficulty maintaining an erection is the earliest, and only, visible symptom of heart disease. This is especially relevant if your boyfriend is over 40, has high blood pressure, high cholesterol, or diabetes, or has a family history of heart problems.
This doesn’t mean every erection issue points to heart disease. But if it’s happening consistently and there’s no obvious psychological or medication-related explanation, it’s worth getting basic bloodwork and a cardiovascular screening. A doctor can check cholesterol, blood sugar, blood pressure, and testosterone levels with simple tests.
The Testosterone Question
Low testosterone is often the first thing people suspect, but the connection is more nuanced than most realize. Testosterone is primarily responsible for sex drive, not the mechanical process of getting or staying hard. Many men with low testosterone still get erections normally but simply don’t feel interested in sex. And many men with perfectly normal testosterone still struggle with erection maintenance.
Treating low testosterone alone rarely fixes erection problems. Mount Sinai researchers note that even among physicians, there’s a common misconception that testosterone therapy will significantly improve erections in men with erectile dysfunction. If low libido is the main issue and blood tests confirm low testosterone, treatment can help. But if the problem is specifically losing an erection during sex, testosterone is unlikely to be the whole answer.
What Actually Helps
Prescription oral medications work for 60% to 70% of men. Sildenafil (Viagra) is taken 30 to 60 minutes before sex on an empty stomach. Tadalafil (Cialis) works best when taken 60 to 120 minutes beforehand and isn’t affected by food. A daily low-dose version of tadalafil is also available for men who prefer not to plan around a pill. These medications work by enhancing the same nitric oxide signaling pathway that drives natural erections, so arousal is still required for them to work.
Pelvic floor exercises (Kegels) strengthen the muscles that help control blood flow to the penis and maintain erections. These are the same muscles he’d use to stop urinating midstream. Contracting and holding them for a few seconds at a time, working up to several sets per day, can improve erection quality over a period of weeks.
For anxiety-driven erection issues, cognitive behavioral therapy with a therapist who specializes in sexual health is one of the most effective interventions. It breaks the worry cycle by retraining the brain’s automatic threat response during sex. Couples therapy can also help if relationship dynamics are contributing to the pressure.
How to Talk About It
Bringing this up the wrong way can make the problem worse. The most important thing is timing: don’t have this conversation in bed, during or immediately after sex, when both of you feel exposed. Choose a low-pressure, private moment when you’re both relaxed and clothed.
Lead with care, not concern about yourself. Saying “I’ve noticed this seems to be stressing you out, and I want to help” lands very differently than “Why can’t you stay hard?” Remind him that millions of men deal with this and that it’s a medical issue with real solutions, not a reflection of his attraction to you or his masculinity.
Expanding your definition of intimacy also takes enormous pressure off the situation. Penetration is one form of sexual connection, but exploring each other’s bodies, focusing on foreplay, and finding what feels good without the goal of maintaining an erection can actually reduce the anxiety enough that erections return naturally. The less an erection feels like a performance requirement, the more likely it is to cooperate.