Erectile Dysfunction: What Causes It and What to Do Next

Why is ED more than a bedroom issue?

An erection depends on a coordinated chain: nerve signals, blood vessel dilation, and blood flow into penile tissue. Almost anything that disrupts blood vessels, nerves, or hormones can interfere. That's why ED is recognized as a potential early marker of cardiovascular disease — the blood vessels supplying the penis are smaller than those supplying the heart, so they often show signs of disease earlier 1Ref 1Burnett AL, Nehra A, Breau RH, Culkin DJ, Faraday MM, Hakim LS, Heidelbaugh J, Khera M, McVary KT, Miner MM, Nelson CJ, Sadeghi-Nejad H, Seftel AD, Shindel AW (2018).Erectile Dysfunction: AUA Guideline.AUA clinical guideline establishing vascular causes as most common, medication side effects, and evaluation framework for ED.

A man who develops ED and has never been evaluated for heart disease or diabetes may be receiving a signal worth taking seriously, independent of the sexual concern itself.

What are the most common causes of erectile dysfunction?

Vascular causes (most common overall)

Conditions that narrow or damage blood vessels reduce blood flow to the penis. These include high blood pressure, high cholesterol, atherosclerosis, type 2 diabetes, and obesity. Smoking is also a significant and independent vascular risk factor 1Ref 1Burnett AL, Nehra A, Breau RH, Culkin DJ, Faraday MM, Hakim LS, Heidelbaugh J, Khera M, McVary KT, Miner MM, Nelson CJ, Sadeghi-Nejad H, Seftel AD, Shindel AW (2018).Erectile Dysfunction: AUA Guideline.AUA clinical guideline establishing vascular causes as most common, medication side effects, and evaluation framework for ED.

Neurological causes

The nerves that signal an erection can be affected by diabetes (peripheral neuropathy), multiple sclerosis, spinal cord injuries, or surgery and radiation to the pelvic area — commonly after prostate cancer treatment.

Hormonal causes

Low testosterone is a commonly discussed cause, though it accounts for a minority of ED cases. Thyroid problems and elevated prolactin can also contribute 3Ref 3Mulhall JP, Trost LW, Brannigan RE, Kurtz EG, Redmon JB, Chiles KA, Lightner DJ, Miner MM, Murad MH, Nelson CJ, Platz EA, Ramanathan LV, Lewis RW (2018).Evaluation and Management of Testosterone Deficiency: AUA Guideline.Testosterone deficiency as a minority cause of ED; hormonal evaluation including prolactin and thyroid as part of workup.

Psychological causes

Anxiety (especially performance anxiety), depression, stress, relationship difficulties, and grief can cause or significantly worsen ED 4Ref 4O'Connor E, Henninger M, Perdue LA, et al. (2023).Screening for Depression and Suicide Risk in Adults: US Preventive Services Task Force Recommendation Statement.Depression as a common contributor to sexual dysfunction; importance of screening for depression in primary care settings. Psychological causes are more likely when ED is situational — present in some contexts but not others (for example, erections occur during sleep but not with a partner).

Medication side effects

Many widely prescribed medications list ED as a known side effect, including certain blood pressure medications (some older beta-blockers and diuretics), antidepressants (particularly SSRIs), antipsychotic medications, and certain hormonal therapies. This does not mean stopping any medication — it means the list is worth reviewing with a clinician 1Ref 1Burnett AL, Nehra A, Breau RH, Culkin DJ, Faraday MM, Hakim LS, Heidelbaugh J, Khera M, McVary KT, Miner MM, Nelson CJ, Sadeghi-Nejad H, Seftel AD, Shindel AW (2018).Erectile Dysfunction: AUA Guideline.AUA clinical guideline establishing vascular causes as most common, medication side effects, and evaluation framework for ED.

Lifestyle factors

Excessive alcohol use, a sedentary lifestyle, poor sleep, and obesity each independently contribute to ED risk.

How does diabetes affect erectile function?

Diabetes damages both blood vessels and nerves — two of the three systems an erection depends on. Men with poorly controlled diabetes have significantly higher rates of ED than the general population 5Ref 5American Diabetes Association Professional Practice Committee (2024).Standards of Care in Diabetes—2024.Diabetes as a major vascular and neurological risk factor for ED; relationship between glycemic control and erectile function. Getting blood sugar under control often improves erectile function, which is one reason the evaluation matters beyond the sexual symptom itself.

When should I see a clinician — and what kind?

Any ongoing ED is worth discussing with a clinician. Primary care is typically the right starting point — your doctor can evaluate your cardiovascular health, screen for diabetes and hormonal issues, review your medications, and have an honest conversation about psychological contributors.

Depending on findings, they may refer you to: - A urologist if the cause appears structural - An endocrinologist if a hormonal imbalance is identified - A mental health professional or sex therapist if psychological factors are significant - A cardiologist if cardiovascular disease is a concern

ED is a common and well-understood medical issue. Clinicians address it regularly and approach it matter-of-factly.

What does treatment look like?

Treatment depends entirely on the cause — which is why evaluation comes before reaching for any solution.

• Lifestyle changes: Weight loss, regular aerobic exercise, quitting smoking, and reducing alcohol each have real effects on erectile function in men with vascular risk factors.
• Treating underlying conditions: Controlling blood pressure, blood sugar, or cholesterol often improves ED.
• Reviewing medications: If a current medication may be contributing, alternatives may be available.
• PDE5 inhibitors: The first-line medical treatment for most men with ED — effective across a broad range of causes 2Ref 2Pyrgidis N, Mykoniatis I, Haidich AB, Tirta M, Talimtzi P, Kalyvianakis D, Ouranidis A, Hatzichristou D (2021).The Effect of Phosphodiesterase-type 5 Inhibitors on Erectile Function: An Overview of Systematic Reviews.PDE5 inhibitors as first-line medical treatment for ED, effective across a broad range of causes. A clinician must prescribe these and will review interactions, particularly with nitrate medications.
• Testosterone replacement: Only appropriate if testing confirms genuinely low testosterone 3Ref 3Mulhall JP, Trost LW, Brannigan RE, Kurtz EG, Redmon JB, Chiles KA, Lightner DJ, Miner MM, Murad MH, Nelson CJ, Platz EA, Ramanathan LV, Lewis RW (2018).Evaluation and Management of Testosterone Deficiency: AUA Guideline.Testosterone deficiency as a minority cause of ED; hormonal evaluation including prolactin and thyroid as part of workup.
• Psychological support: Therapy for anxiety, depression, or relationship factors can be highly effective — sometimes more so than medication.
• Vacuum devices, penile injections, or surgical implants: For men who don't respond to the above, a urologist can discuss these options.