Erectile Dysfunction UK: Causes, Symptoms & Treatment

Erectile dysfunction is the most common sexual health concern reported by men in the UK — yet it remains significantly underreported due to stigma. Despite its prevalence, effective MHRA-approved treatments are available and accessible without a GP appointment. This condition guide covers everything clinically relevant: how erections work, what causes them to fail, how to recognise ED, its relationship with wider health conditions, and the full range of treatment options. Use the section links above to explore specific topics in depth.

How Erections Work — and Why They Fail

For an erection to occur, a coordinated sequence of events must happen in the right order. Sexual stimulation — physical or psychological — triggers the release of nitric oxide in the penis. This causes smooth muscle in the penile arteries to relax, widening them and allowing blood to flood into the two spongy chambers of the penis (the corpus cavernosum). The chambers expand, compress the veins draining the penis, and the result is a firm erection.

Erectile dysfunction occurs when this process is disrupted at any stage — by insufficient blood flow, nerve damage, hormonal imbalance, or psychological interference. The PDE5 enzyme normally breaks down the signal that keeps arteries relaxed; PDE5 inhibitors (sildenafil, tadalafil) work by blocking this enzyme, making it easier for the process to complete.

How Common Is Erectile Dysfunction?

ED is significantly more common than most men realise. Estimates suggest approximately 4.3 million men in the UK experience ED to some degree. Prevalence increases with age — affecting around 40% of men at age 40 and up to 70% of men over 70 — but it is by no means exclusively a condition of older men. Around 1 in 4 new ED presentations in UK sexual health clinics are in men under 40.

Despite its prevalence, ED remains substantially underreported. Many men do not seek help due to embarrassment or a belief that little can be done. In reality, the vast majority of men with ED can achieve satisfactory erections with appropriate first-line treatment.

What Causes Erectile Dysfunction?

ED has three main categories of cause, which frequently overlap and interact:

Physical Causes

• Cardiovascular disease — atherosclerosis narrows penile arteries; ED is often an early marker of vascular disease
• Diabetes — damages both blood vessels (vasculopathy) and nerves (neuropathy) that erections depend on; affects up to 75% of diabetic men over a lifetime
• Hypertension — damages arterial walls and reduces penile blood flow
• Obesity — associated with low testosterone, insulin resistance, and endothelial dysfunction
• Low testosterone (hypogonadism) — reduces libido and may impair erectile response
• Neurological conditions — multiple sclerosis, Parkinson’s disease, spinal cord injury, post-surgical nerve damage
• Sleep apnoea — reduces nocturnal testosterone and oxygen delivery

Psychological Causes

• Performance anxiety — the most common cause in men under 40; creates a self-reinforcing cycle
• Depression and generalised anxiety — disrupt neurological and hormonal pathways needed for arousal
• Relationship difficulties — communication issues, emotional distance, unresolved conflict
• Stress — chronic stress elevates cortisol, suppressing testosterone and sexual function

Medication-Induced Causes

• Antidepressants (particularly SSRIs)
• Beta-blockers and some antihypertensives
• Thiazide diuretics
• Antiandrogens and some prostate medications
• Opioid analgesics

For a full breakdown, see: What Causes Erectile Dysfunction? and Psychological Erectile Dysfunction.

Symptoms and Diagnosis

The defining feature of ED is difficulty achieving or maintaining an erection sufficient for satisfactory sex, occurring persistently over at least several weeks. Associated features may include reduced libido, absent nocturnal erections, and in some cases premature ejaculation or delayed ejaculation.

Key Diagnostic Indicators

• Consistent difficulty achieving or maintaining erection — not occasional
• Absent nocturnal erections — strongly suggests a physical cause; their presence points to psychological
• Situational pattern — ED in some contexts but not others points to psychological contribution
• Sudden onset — especially after a stressful event, suggests psychological; gradual onset suggests physical
• Associated cardiovascular risk factors — hypertension, diabetes, obesity, smoking

Clinical Assessment

A thorough ED assessment includes blood pressure, fasting blood glucose, lipid profile, testosterone (morning sample), thyroid function where indicated, and a brief psychological screen. Access Doctor’s online consultation covers this clinical history as part of the prescribing assessment.

For a detailed guide, see: Signs of Erectile Dysfunction: How to Know If You Have ED.

Treatment Options

NICE recommends oral PDE5 inhibitors as first-line pharmacological treatment for erectile dysfunction. All four MHRA-approved options work by blocking the PDE5 enzyme in penile blood vessels, allowing blood flow to increase when sexually stimulated. Sexual stimulation is always required — none of these medications produces an automatic erection.

Second-Line Options

• Alprostadil — penile injection (MUSE urethral suppository or intracavernosal injection); bypasses the nitric oxide pathway; ~85% success rate in diabetic men; useful where PDE5 inhibitors are contraindicated or insufficient
• Vacuum erection device (VED) — non-pharmacological; effective in ~75% of men; no drug interactions or systemic effects
• Psychological therapy — CBT and sex therapy are highly effective for psychological ED; often used alongside short-term medication to restore confidence
• Testosterone replacement therapy (TRT) — indicated where confirmed hypogonadism is contributing; improves libido and may improve PDE5 inhibitor response

Lifestyle Changes

For men with modifiable risk factors, lifestyle changes can significantly improve erectile function — and in some cases resolve ED without medication. See: Lifestyle Changes for Erectile Dysfunction.

• Weight loss — even 5–10% reduction in body weight improves vascular and hormonal function
• Aerobic exercise — 3× weekly significantly improves erectile function in men with cardiovascular risk factors
• Stopping smoking — smoking accelerates arterial narrowing; stopping improves penile blood flow
• Alcohol reduction — heavy alcohol use acutely and chronically impairs erectile function

Erectile Dysfunction and Wider Health

ED is rarely an isolated condition. It is strongly associated with cardiovascular disease, diabetes, obesity, depression, and hormonal disorders — and frequently serves as an early warning sign for these conditions. Understanding the relationship between ED and overall health is central to good clinical management.

All Four MHRA-Approved ED Medications

NICE recommends four oral PDE5 inhibitors for ED. All work through the same fundamental mechanism but differ meaningfully in onset, duration, food interaction, and tolerability profile. The right choice depends on lifestyle, frequency of activity, and individual response.

For a full head-to-head comparison, see: Viagra vs Cialis vs Levitra vs Stendra and Tadalafil vs Sildenafil: Which Is Better?

The Most Important Safety Warning: Nitrates

All four PDE5 inhibitors share one absolute contraindication with no exceptions: they must never be combined with nitrate medicines in any form. This combination causes a severe, potentially fatal drop in blood pressure.

For a full safety reference including all drug interactions, see: Sildenafil: Dosage, Side Effects, Contraindications & Drug Interactions.

All Erectile Dysfunction Guides

Our full library of 23 clinically reviewed guides, medically authored by Dr Abdishakur M Ali (GMC no. 7041056), NICE-referenced and GPhC-aligned.

Understanding ED — Condition Guides

ED and Health Conditions

Treatment Approach & Lifestyle

Medication Comparisons

Sildenafil (Viagra)

Tadalafil (Cialis)

Vardenafil (Levitra) & Avanafil (Spedra)