Overview
Erectile dysfunction (ED) is the persistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance. It is a symptom and not a disease and is due to underlying causes.
Although its causes are often mixed, they can be divided into primarily organic and primarily psychogenic causes.
Epidemiology
Accurate data is difficult to find as many patients do not seek help, however:
- Erectile dysfunction is very common and incidence increases with age
- Incidence is common in people aged 40-70 years old
Causes
Organic causes include:
- Vascular problems – cardiovascular disease, hyperlipidaemia, hypertension, diabetes mellitus, obesity, smoking, metabolic syndrome
- Neurogenic:
- Central causes – multiple sclerosis, Parkinson’s disease, multiple system atrophy and other Parkinson-plus syndromes
- Peripheral causes – diabetes mellitus, chronic kidney disease, trauma during pelvic surgery
- Anatomical/structural – phimosis, Peyronie’s disease, prostate/penile cancer, micropenis, hypospadias, congenital curvature of the penis
- Endocrine – diabetes mellitus, hypogonadism, hyperprolactinaemia, hyper- and hypothyroidism, Cushing’s syndrome, hypopituitarism
Psychogenic causes include:
- Generalised – lack of sexual desire
- Situational – partner/performance-related issues, stress, depression, anxiety, psychosis
Drugs that can cause or worsen symptoms include:
- Alcohol
- Antidepressants – often selective serotonin reuptake inhibitors (SSRIs)
- Diuretics – thiazides, spironolactone
- Beta-blockers
- Anticholinergic drugs
- Antipsychotics
Investigations and Referral
Investigations
All people should have blood tests for an underlying cause. These include:
- HbA1c or fasting glucose:
- To screen for diabetes mellitus
- Serum lipid profile and QRISK calculation:
- To identify hyperlipidaemia and assess risk of cardiovascular disease
- Free testosterone (ideally between 9-11 am):
- To screen for testosterone deficiency and hypogonadism
- If low/borderline, arrange repeat test and include follicle–stimulating hormone (FSH), luteinizing hormone (LH), sex hormone binding globulin, and prolactin levels.
Referral
If any of the following apply, refer the patient to an appropriate specialist in secondary care:
- Urology:
- The person is young/has a lifelong history of difficulties with erection
- History of pelvic, perineal, or genital trauma
- Anatomical/structural abnormalities of the penis or testis on examination
- Endocrinology:
- If hypogonadism is suspected (low testosterone) or there are abnormalities in FSH, LH, or prolactin
- Cardiology:
- If cardiac risk is high and sexual activity is unsafe or phosphodiesterase-5 (PDE-5) inhibitor use is contraindicated
Management
Overview
If referral is not indicated, management involves lifestyle changes and phosphodiesterase-5 (PDE-5) inhibitors (such as sildenafil, also known as Viagra):
- They should be prescribed regardless of aetiology as long as they are not contraindicated
If PDE-5 inhibitors are ineffective, not tolerated, or contraindicated, offer a referral to urology where they may consider specialist options such as vacuum erection assistant devices.
Monitoring
Lifestyle advice may involve, if indicated:
- Weight loss and regular exercise
- Smoking cessation
- Alcohol reduction
- Stopping all sexual activity if a cardiology assessment has been arranged and a person is at high cardiac risk
- Stopping cycling for a trial period if people cycle for >3 hours a week
