Erectile Dysfunction: Causes, Treatments & When to Seek Help

What is erectile dysfunction?

Erectile dysfunction (ED) is defined as the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity. According to NICE Clinical Knowledge Summaries (CKS), ED is diagnosed when the problem occurs regularly and causes personal distress. While occasional difficulty is normal, persistent ED warrants clinical assessment.

It is important to recognise that ED is a medical condition — not a personal failing — and is highly treatable in the vast majority of cases. Seeking help early is also clinically significant, as ED can be an early marker of underlying cardiovascular disease.

How common is ED in the UK?

ED is far more prevalent than is often acknowledged. NICE CKS reports that ED affects approximately 40% of men aged 40, increasing to around 70% by age 70. Despite this, many men delay seeking treatment due to embarrassment.

Online pharmacies like Medicinex offer a discreet, clinician-reviewed pathway to treatment without the need for an in-person GP appointment, in accordance with GPhC guidance on online prescribing.

Causes and risk factors

ED can have physical, psychological, or mixed causes. In men over 40, physical (organic) causes predominate. NICE CKS outlines the following key contributing factors:

Physical causes

• Cardiovascular disease and atherosclerosis — reduced blood flow to penile arteries is the most common organic cause
• Diabetes mellitus — affects up to 50% of men with diabetes due to vascular and nerve damage
• Hypertension and certain antihypertensive medications (e.g. thiazides, beta-blockers)
• Obesity and metabolic syndrome — associated with low testosterone and endothelial dysfunction
• Hypogonadism (low testosterone) — assessed via morning serum testosterone measurement
• Neurological conditions (e.g. multiple sclerosis, spinal cord injury)
• Medications — including SSRIs, anti-androgens, and some diuretics
• Smoking and excessive alcohol consumption

Psychological causes

• Performance anxiety
• Depression and generalised anxiety disorder
• Relationship problems
• Past sexual trauma

Diagnosis and when to see a doctor

NICE CKS recommends a structured clinical assessment including: sexual and medical history, medication review, and baseline investigations including fasting lipids, HbA1c, and a morning serum testosterone level. Blood pressure should also be measured at presentation.

You should seek medical advice if:

• ED is persistent and causing distress
• You have other symptoms such as reduced libido, fatigue, or low mood
• You have known cardiovascular risk factors or have not had a recent cardiovascular check
• ED began after starting a new medication
• You are under 40 with no obvious risk factors (specialist referral may be appropriate)

Treatment options: PDE5 inhibitors

NICE CKS recommends phosphodiesterase type 5 (PDE5) inhibitors as the first-line pharmacological treatment for ED in the absence of contraindications. These medicines enhance the natural erectile response to sexual stimulation — they do not produce erections in the absence of arousal.

The BNF lists sildenafil, tadalafil, vardenafil, and avanafil as licensed PDE5 inhibitors available in the UK. All require a valid prescription from a registered prescriber.

Sildenafil vs tadalafil: which is right for you?

The two most commonly prescribed PDE5 inhibitors in UK primary care are sildenafil and tadalafil. NICE CKS and South West London ICB formulary guidance both recommend generic sildenafil as first-line, with tadalafil as an alternative where its longer duration is clinically appropriate.

For men who prefer spontaneity, tadalafil's longer window of action may be more suitable. Sildenafil remains the most cost-effective on-demand option and is widely used in UK primary care. Both are available through Medicinex following a clinician-reviewed consultation.

Lifestyle changes that improve ED

NICE CKS emphasises lifestyle optimisation as an integral part of ED management, irrespective of pharmacological treatment. Addressing modifiable risk factors can meaningfully improve erectile function and overall cardiovascular health:

• Regular aerobic exercise — evidence supports 40 minutes of moderate-to-vigorous activity four times weekly; improves endothelial function and reduces ED severity
• Weight loss — in overweight or obese men, weight reduction improves testosterone levels and endothelial function
• Smoking cessation — smoking is an independent risk factor for ED through vascular mechanisms
• Reducing alcohol — both acute intoxication and chronic heavy use impair erectile function
• Optimising cardiovascular risk — treatment of hypertension, dyslipidaemia, and diabetes can improve ED concurrently

The psychological side of ED

Even when ED has a primarily physical cause, a psychological component frequently develops. NICE CKS recommends that psychosexual counselling or cognitive behavioural therapy (CBT) be considered, particularly for men with predominant psychological ED or significant performance anxiety.

Many men find that effectively treating the physical component with medication simultaneously reduces performance anxiety. Referral to a psychosexual service should be considered when psychological factors are prominent or when pharmacological treatment alone is insufficient.