What causes erectile dysfunction?

There are many causes of erectile dysfunction (ED), including problems with blood flow, nerve signals, or hormones, and psychological causes like stress, anxiety, and depression. Certain medicines can also play a part, and these causes often overlap.

Some studies show that as many as 30% of men under 40 have had erection difficulties (Nguyen et al., 2017). A doctor can help work out what's behind yours and what to try next.

If you're not sure your symptoms point to ED at all, start by recognizing the symptoms of ED first.

The main types of ED

ED can come from several pathways, including psychological, vascular, neurological, and hormonal causes (Cleveland Clinic, 2023).

Source for this table: (Cleveland Clinic, 2023).

Does psychological stress cause ED?

It can. Performance anxiety can override the normal signals that lead to an erection. Dr. Shannon Chavez, a clinical psychologist who specializes in performance anxiety, calls this a nervous system problem. Once your body goes on high alert, it stops focusing on arousal and starts focusing on threat, and an erection becomes harder to reach.

Psychological factors are a common cause of ED. However, one review reported that as many as 87% of young men with ED also have a physical component, such as a blood flow, nerve, hormone, or medication-related cause (Nguyen et al., 2017). Psychological and physical causes often overlap, so it's worth seeing a doctor even if you think stress is behind it.

If you want to know more about this side of ED, read up on psychological ED treatment options.

Vascular and cardiovascular causes

Erections need healthy blood flow, so anything that narrows or blocks the blood vessels involved can get in the way. Heart disease, high blood pressure, high cholesterol, and diabetes are possible causes here.

The link works both ways. ED might be an early warning sign of cardiovascular disease, since the same blood vessels are affected in both (Yafi et al., 2016). Because of this link, official urology guidelines recommend checking for cardiovascular risk factors in any man who presents with ED (Burnett et al., 2018).

Stroke is a clear example of this connection. Studies suggest that men who have had a stroke have 3.32 times the relative risk of ED compared with men who haven't, and pooled studies put ED in stroke survivors between 32.1% and 77.8% (Zhao et al., 2021).

Hormonal causes

Hormones regulate many bodily functions, including desire and physical function, so a shift in the wrong direction can cause ED even when blood flow and nerve signals are working fine. Low testosterone can reduce both desire and erectile function. High prolactin can cause low libido and ED alongside symptoms like headaches. Thyroid problems can affect circulating sex hormone levels that may also reduce sexual function.

Because many hormonal causes are common and treatable, testosterone testing is recommended for every man who presents with ED, whatever his profile (Burnett et al., 2018).

Can medications cause ED?

Yes, several types of medication are linked to ED, though the risk and the reason vary by drug and the person taking it. Certain blood pressure medications, some antidepressants, opioid painkillers, and a handful of other drug classes appear on most clinical lists of medications linked to erectile problems. Medicines usually cause ED by affecting the hormone, nerve, or blood flow pathways above. Among blood pressure medicines, older beta-blockers are the ones most linked to ED, while others are neutral or may even help (Corona et al., 2024).

Selective serotonin reuptake inhibitors (SSRIs), a common type of antidepressant, are linked to sexual side effects, including problems with desire, arousal and erections, and orgasm (Nelson et al., 2026). If you think a medication is affecting your erections, don't stop taking it on your own. Talk to your doctor, who can go through your options with you.

What are the risk factors for ED?

Risk factors are things that make ED more likely. Recognized risk factors include age, smoking, diabetes, high blood pressure, high cholesterol, depression, obesity, and an inactive lifestyle, and many of them are also risk factors for heart disease (Burnett et al., 2018).

Health conditions

• Diabetes. A review of 145 studies found that about half of men with diabetes (52.5%) have ED (Kouidrat et al., 2017).
• High blood pressure. High blood pressure often goes hand in hand with ED and can help cause it (Burnett et al., 2018).
• Depression. Depression and ED are closely linked in both directions (Liu et al., 2018). Read more about depression and erectile dysfunction.
• Prostate cancer surgery. Surgery to remove the prostate is a known cause of ED. Across 268 studies, the share of men whose erections recovered ranged from 12% to 67%, depending on the type of surgery and the time since it (Moretti et al., 2024).

Lifestyle factors and recreational drugs

• Smoking. In studies that followed men over time, current smokers had about 51% higher odds of ED than men who had never smoked (Cao et al., 2013).
• Weight. In a review of 45 studies and over 42,000 men, men with obesity had 46% higher odds of ED than men at a typical weight, after accounting for other factors (Pizzol et al., 2020).
• Alcohol. US health guidance lists drinking too much alcohol as something that may contribute to ED (NIDDK, 2024). Large reviews of long-term drinking habits show a less clear-cut picture, and because those studies are observational, they can't show whether alcohol itself raises or lowers risk (Li et al., 2021).
• Recreational drugs. European urology guidelines list recreational drugs, including cocaine, heroin, and cannabis, as possible causes of ED (EAU, n.d.). For more on one of these, read about cocaine and erection problems.
• Cycling. Long hours on a bike saddle can cause temporary numbness. The evidence linking cycling to ED is limited and conflicting, and moderate cycling seems to be a smaller risk than smoking, high blood pressure, or age (SMSNA, n.d.). If cycling is a big part of your life, read more on how cycling affects erectile function.

A healthier diet and more physical activity may improve erections in men who have ED alongside other health conditions (Burnett et al., 2018).

When ED points to something more serious

Persistent ED, especially in men under 40, is worth mentioning to a doctor rather than managing alone. It can be an early marker of cardiovascular or metabolic disease, and catching that early is far more important than the ED itself (Burnett et al., 2018).

Many men put this conversation off. One consumer survey found that 39% of men with ED never sought treatment for it (SingleCare, 2020). A GP visit can rule out or confirm a physical cause quickly, and it's the right first step if you haven't had one yet. Read more on how ED is diagnosed.

The Erection Reset's approach to psychological ED

A doctor can help diagnose any type of ED, including psychological ED, and can help with treatment. For psychological ED, that can include talk therapy or sex therapy.

The Erection Reset is Mojo's expert-led program, built by Dr. Shannon Chavez, and it's designed as a supportive tool for psychological ED. It's evidence-based and structured around understanding performance anxiety, retraining your response to sex, and rebuilding confidence step by step. It isn't a treatment for vascular, neurological, or hormonal ED, and it doesn't replace care from your doctor.

If you want to compare every option available to you first, see the full range of treatment options for erectile dysfunction.