Erectile dysfunction often has more than one cause. This guide explains the vascular, metabolic, hormonal, neurological, psychological and medication factors clinicians assess.
Erectile dysfunction usually develops through a combination of factors rather than one isolated cause. Blood-vessel disease and metabolic conditions are common contributors, but nerves, hormones, penile structure, medicines, mental health and relationship context can all affect erections. Identifying the likely contributors guides treatment and can reveal health risks that need attention in their own right.
| Category | Examples | What an assessment may look for |
|---|---|---|
| Vascular and metabolic | Diabetes, high blood pressure, high cholesterol, smoking, obesity, cardiovascular disease | Gradual or consistent ED, cardiovascular risk factors, abnormal blood pressure, glucose or lipids |
| Neurological | Spinal cord injury, multiple sclerosis, Parkinson’s disease, stroke, diabetic neuropathy | Neurological symptoms, relevant diagnosis, injury or surgery |
| Hormonal | Testosterone deficiency and, less commonly, other pituitary or endocrine disorders | Low libido, fatigue or physical signs alongside correctly timed hormone tests |
| Structural or treatment-related | Peyronie’s disease, pelvic trauma, prostate or pelvic surgery, pelvic radiotherapy | Curvature, pain, shortening, scar tissue or a clear link with an operation or injury |
| Psychological and relational | Performance anxiety, stress, depression, relationship conflict, previous sexual trauma | Situational pattern, rapid onset, anxiety, mood symptoms or preserved erections in other settings |
| Medication or substance-related | Some antidepressants, blood-pressure treatments, anti-androgen treatment, excess alcohol and recreational drugs | Symptoms beginning after a dose or medicine change, drug interactions or substance use |
The clues in this table are not diagnostic. For example, morning erections can persist in a man with a physical cause, and anxiety can occur after physically caused ED. A proper assessment considers the whole pattern.
An erection requires arteries in the penis to dilate and deliver enough blood. Conditions that impair the lining of blood vessels or narrow arteries can reduce that response. Relevant factors include:
These factors can occur together. A man may first notice unreliable erections without having chest pain or another obvious cardiovascular symptom. This is why a consultation for recurring ED should include a general health assessment rather than focusing only on an erection tablet.
Diabetes can affect erection quality through several pathways. Persistently raised glucose may damage small blood vessels and the autonomic nerves involved in erections. Diabetes is also associated with cardiovascular risk, kidney disease, medication use and sometimes testosterone deficiency, all of which may contribute.
ED in a man with diabetes is not evidence of poor effort or personal failure. Good management of glucose and cardiovascular risk is important for long-term health and may support sexual function, but some men still require specific ED treatment.
ED is recognised as a cardiovascular risk marker. The EAU guideline reports an association between ED and later cardiovascular events and recommends cardiovascular risk assessment, especially when the pattern appears predominantly vascular. NICE’s UK cardiovascular guideline recommends QRISK3 for formal risk assessment in eligible adults aged 25 to 84 without established cardiovascular disease. QRISK3 includes erectile dysfunction because older tools may underestimate risk in this group.
This association should be interpreted carefully:
A clinician may check blood pressure, smoking status, family history, weight or waist measurement, cholesterol and glucose or HbA1c. Men with exertional chest pain, unusual breathlessness, fainting or unstable heart disease need assessment of whether sexual activity and ED medicines are safe.
Erections depend on nerve signals between the brain, spinal cord, pelvic nerves and penis. ED can follow spinal cord injury, stroke, multiple sclerosis, Parkinson’s disease, pelvic nerve damage or diabetic neuropathy. The pattern depends on which pathways are affected, so libido, sensation, ejaculation and orgasm may be normal or altered.
New ED accompanied by weakness, numbness, bladder or bowel disturbance, severe back symptoms or other neurological change should not be assumed to be a routine sexual problem. Seek medical advice promptly.
Testosterone contributes to sexual desire and supports normal sexual function. Confirmed testosterone deficiency can be associated with reduced libido, fewer spontaneous erections and ED. It is more likely when ED occurs alongside symptoms such as persistently low desire or other compatible clinical features.
Diagnosis cannot be made from symptoms alone or from an untimed single result. The EAU recommends an early-morning total testosterone measurement as part of the metabolic and hormonal assessment of ED. A low result needs interpretation and usually repeat testing in line with testosterone-deficiency guidance. Further tests, such as luteinising hormone or prolactin, are selected according to the clinical picture.
Giving testosterone to a man whose testosterone is not deficient is not a standard ED treatment. It may expose him to harm without addressing the actual cause.
Erection nerves and blood vessels run close to the prostate and other pelvic structures. Radical prostatectomy, pelvic radiotherapy and some other pelvic procedures can affect them. Recovery varies according to baseline erections, age, the treatment used, whether nerves could be spared and other health factors.
Men planning prostate-cancer treatment should be told about possible changes in erections, desire, ejaculation, orgasm and penile shape or length. Early access to sexual rehabilitation and ED treatment can help men and partners adapt, although taking a PDE5 inhibitor after surgery does not guarantee recovery of unassisted erections.
Peyronie’s disease involves scar tissue within the penis and may cause a new curve, indentation, shortening, pain or difficulty with penetration. ED may develop because the penile tissue does not expand normally, because the deformity makes sex difficult or because anxiety develops around the change.
A new bend, palpable plaque, pain during erection or significant shortening merits a clinical examination. Photographs taken privately at home may help a urology assessment, but do not send intimate images unless a regulated clinical service has specifically explained a secure process.
Erection is sensitive to attention, mood and the body’s stress response. Performance anxiety can shift attention towards monitoring firmness and away from arousal. Depression may reduce desire and responsiveness; relationship conflict, grief, work pressure, body-image concerns and previous sexual trauma can also contribute.
A sudden, situational pattern with preserved erections at other times can point towards a strong psychological component, but clinicians should still consider general health and medicines. Psychosexual therapy or cognitive behavioural therapy can be used alone or alongside physical treatment. Involving a partner is optional and should be based on the patient’s circumstances and consent.
Sexual side effects are reported with several drug groups, including some antidepressants, antihypertensives, antipsychotics, anti-androgen treatments, 5-alpha-reductase inhibitors and opioids. The likelihood differs between medicines and between individuals. The underlying condition may itself affect erections, which makes cause and effect difficult to separate.
If symptoms began after starting or changing a medicine:
Stopping antidepressants, heart medicines or hormone treatment abruptly can be unsafe.
Acute intoxication may impair arousal, nerve signalling and erection quality. Longer-term heavy alcohol use can contribute through liver disease, hormone changes, nerve damage and relationship or mental-health effects. Smoking damages blood vessels and is a modifiable risk factor for ED and cardiovascular disease.
Recreational drugs may affect erections directly or through anxiety, cardiovascular effects and unsafe interactions. Nitrite “poppers” must never be combined with PDE5 inhibitors because both lower blood pressure through related pathways.
Age increases the probability of conditions and medicines that affect erections, and erectile tissue changes over time. Age alone does not explain every case and is not a reason to deny assessment. New or worsening ED in an older man still warrants review of cardiovascular risk, diabetes, medicines, hormones when indicated and sexual context.
It depends on the cause and the extent of any established nerve or blood-vessel damage. Potentially helpful measures include:
Lifestyle changes should be offered without implying that a man caused his ED. Improvement is variable, and delaying effective ED treatment until every risk factor is “perfect” is not required.
Prostate surgery can affect the nerves and blood vessels needed for erections. Recovery is individual and may take time. A urology or sexual-medicine team can discuss tablets, vacuum devices, injections and, when appropriate, implants.
