
Men’s health › ED causes and treatments
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The short version. An erection is a vascular event. That single fact explains most of what follows: why ED is common, why it rises with age, why it tracks with heart disease and diabetes, and why the most consequential thing about an ED diagnosis is often what it reveals about the rest of your circulation. Pills work for many men. They also treat the symptom, and the AUA is clear that the symptom deserves a workup.
How an erection works
Mayo Clinic describes the anatomy plainly: the penis contains “two cylinder-shaped, spongelike structures called the corpora cavernosa”, and during arousal “nerve impulses increase blood flow to both cylinders. This sudden influx of blood causes an erection by expanding, straightening and stiffening the penis.”
The FDA label for Cialis gives the cleanest description of the chemistry: “Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum.”
Nitric oxide, cGMP, smooth muscle relaxation, blood flow. Anything that interferes with nerves, blood vessels, hormones or the signal itself can interrupt the chain.
How common it is
The NIDDK states that “research suggests that between 30 million and 50 million men in the United States have ED”, and that “at age 40, about 40% of men are affected, while 70% report having ED by age 70.”
Worth a caveat: those age figures trace back to the Massachusetts Male Aging Study, a survey from 1994. They are the most-cited numbers in the field and they are indicative rather than precise.
What causes it
The NIDDK groups the organic causes:
- Vascular — “heart and blood vessel diseases, such as atherosclerosis, high blood pressure, and stroke.” This is the largest group.
- Neurogenic — “nerve damage or disorders, such as multiple sclerosis, spinal cord injuries, and damage from pelvic surgery.”
- Hormonal — “hormone issues, such as low testosterone and thyroid imbalance.”
- Other conditions — diabetes, chronic kidney disease, obesity, COPD, enlarged prostate, Peyronie’s disease.
Medication is an under-recognised cause. The NIDDK names antidepressants, appetite suppressants, antihistamines, blood pressure medicines and diuretics, chemotherapy and hormone medicines, pain relievers including NSAIDs and opioids, sedatives, and ulcer medicines. If ED began after a new prescription, that sequence is worth raising with whoever wrote it.
Psychological factors are real and not separate. The NIDDK notes that “some mental health or emotional issues can either cause ED or make it worse” — anxiety, depression, stress, isolation, low self-esteem. In practice most cases are mixed: a physical change starts it, anxiety about the change maintains it.
The part most articles bury
Mayo Clinic explains the mechanism: “Because the penile arteries are only 1 to 2 mm wide, they’re among the first vessels to show signs of atherosclerosis”, and “in many cases, ED is the earliest — and only — visible symptom of cardiovascular disease.” Their clinical summary notes that ED “often occurs 2 to 5 years before men experience heart attacks.”
The primary study behind that lead time is Montorsi and colleagues in European Urology in 2003: among 147 men who had both ED and angiographically confirmed coronary artery disease, ED came first in 99 of them, by a mean of 38.8 months.
This is the strongest argument against buying pills from a form that never asks about your blood pressure, your cholesterol or your family history. Not because the pills do not work — because the question they leave unasked can matter more than the one they answer.
What a proper evaluation involves
AUA Statement 1: “Men presenting with symptoms of ED should undergo a thorough medical, sexual, and psychosocial history; a physical examination; and selective laboratory testing.”
Statement 4 adds a specific test: “In men with ED, morning serum total testosterone levels should be measured.” Morning, because testosterone follows a daily rhythm — see how to read a testosterone test.
The treatment options, in full
The AUA guideline lists these as options a man should be informed about, which is deliberate wording.
| Option | AUA strength | Notes |
|---|---|---|
| Oral PDE5 inhibitors | Strong recommendation, Grade B | Sildenafil, tadalafil and others. See the label comparison. |
| Vacuum erection device | Moderate, Grade C | Non-drug, no systemic effects, works independently of the NO pathway. |
| Intracavernosal injection | Moderate, Grade C | Effective where oral agents fail, including after prostate surgery. |
| Penile prosthesis | Strong recommendation, Grade C | Surgical. High satisfaction in appropriate candidates. |
| Mental health referral | Moderate, Grade C | To “reduce performance anxiety” and support adherence. |
| Lifestyle change | Moderate, Grade C | Diet and activity “improve overall health and may improve erectile function.” |
Treating the cause, not only the symptom
The NIDDK’s first-listed interventions are not drugs: quitting smoking, limiting or stopping alcohol, increasing physical activity, maintaining a healthy weight, following a healthy eating plan, stopping recreational drug use. Where ED is vascular, these act on the actual problem. Where a medication is the cause, changing it may resolve it. Where testosterone is genuinely low, treating that is a different pathway — see what TRT is.
Sources
- NIDDK, “Definition & Facts for Erectile Dysfunction”, reviewed October 2024 — niddk.nih.gov
- NIDDK, “Symptoms & Causes of Erectile Dysfunction” — niddk.nih.gov
- NIDDK, “Treatment for Erectile Dysfunction” — niddk.nih.gov
- American Urological Association, “Erectile Dysfunction: AUA Guideline”, approved April 2018 — auanet.org
- Mayo Clinic, “Erectile dysfunction — Symptoms and causes”, 1 March 2025 — mayoclinic.org
- Mayo Clinic, “Erectile dysfunction: A vital sign for cardiovascular health”, 26 June 2025 — mayoclinic.org
- FDA prescribing information, CIALIS (tadalafil), rev. 02/2018 — accessdata.fda.gov
- Montorsi F, Briganti A, Salonia A, et al. Eur Urol 2003;44(3):360–4. PMID 12932937 — pubmed.ncbi.nlm.nih.gov
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Medical disclaimer. This article is for general information only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any condition. Prescription treatments require evaluation by a US-licensed clinician, who decides whether treatment is appropriate for you. Talk to your own healthcare provider before starting, stopping or changing any medication. Individual results vary.