Erectile dysfunction is a common condition and its frequency increases with age. Whilst for some men it may only occur occasionally, being related to fatigue, stress or alcohol intake, for others, it can occur more frequently. The male erection is the culmination of two aspects of sexual function – a reflex aspect, controlled by the nerves in the body, and a psychogenic aspect, which is the result of emotional or erotic stimuli, and involving the brain’s limbic system (which controls emotions and feelings).
Some men with erectile dysfunction report having either a partial erection that is unable to sustain sexual intercourse, or the total absence of swelling of the penis. The severity of erectile dysfunction can be assessed using the International Index of Erectile Function (IIEF-5), which uses a questionnaire to grade ED as either mild, moderate or severe.
Whilst erectile dysfunction may be related to both mental and physical disorders, in approximately 80% of cases, medical conditions may play a contributory role. It is therefore important for all patients experiencing erectile dysfunction to be reviewed by their GP.
Physical disorders associated with erectile dysfunction can sometimes be related to hormones in the body. Non-hormonal causes include conditions that affect the blood supply to the penis (such as high blood pressure, type 1 or type 2 diabetes and smoking) and those that affect the nerves supplying the penis (such as Parkinson’s disease and damage to the nerves in the body e.g. due to both type 1 or type 2 diabetes). Erectile dysfunction can also be a side-effect of a medical intervention or treatment. Potential treatments that may be implicated in the cause of erectile dysfunction include certain antidepressants and treatment for high blood pressure (antihypertensives).
Some endocrine conditions are associated with erectile dysfunction and include those that cause a low testosterone level (hypogonadism), although the mechanism by which this results in erectile dysfunction is not yet fully known, and some men can continue to have normal sexual function despite low levels of testosterone. Prolactin is a hormone produced by the pituitary gland within the brain. Certain conditions can cause a raised prolactin level (hyperprolactinaemia), which can suppresses the production of other hormones (called luteinising hormone, LH, and follicle stimulating hormone, FSH) from the pituitary gland, and therefore in turn result in low testosterone levels. Low testosterone levels can subsequently predispose to erectile dysfunction.
In addition to physical causes, mental health conditions may also be associated with impotence. These include depression, anxiety and stress, as well as relationship difficulties. Regardless of the underlying cause of erectile dysfunction, it can often have a significant impact on relationships and quality of life.
Erectile dysfunction is the inability to either achieve or maintain an erection. This may happen either occasionally or regularly, but may occur only in certain situations depending on the cause (i.e. patients may still have early morning erections).
Where erectile dysfunction is predominantly due to a physical cause, patients may describe a gradual onset of symptoms, which may occur across a variety of settings and different stimuli. Where the psychological component is the main factor, patients may describe a sudden onset in symptoms with erectile dysfunction varying dependent on the situation.
Depending on the cause of impotence, there may be other signs and symptoms present. For example, where hypogonadism (low testosterone) is the cause, patients may additionally describe reduced sex-drive (low libido), reduced need to shave facial hair and reduced muscle mass. If diabetes has caused damage to the nerve or blood supply to the penis, patients may also describe other symptoms suggestive of damage to other blood vessels or nerves, such as numbness and tingling of the feet.
Erectile dysfunction is common and becomes increasingly more so with age. Complete impotence occurs in 5% of men aged 40 years and 15% of men aged 70 years old. Milder forms of impotence can affect 50% of men aged 50 years old, increasing to 70% of men over 70 years old.
Erectile dysfunction itself is not inherited. However, some of the underlying physical causes may run in families (for example, type 2 diabetes has a genetic predisposition).
The diagnosis of erectile dysfunction is made clinically, based on a patient’s symptoms. It therefore is important for patients to be evaluated by their GP in the first instance. At this appointment, a full history will be taken from the patient regarding the current symptoms and other medical issues. Regular medications will also be reviewed to ensure that there are no contributing factors. Questions regarding alcohol intake and smoking will also be asked. A general physical examination will be performed by the GP, which may include checking blood pressure and an examination of the genitals. Examination of the vascular system and peripheral nervous system may also be undertaken.
Given that erectile dysfunction can be a sensitive marker of vascular pathology, it is also recommended that all patients with erectile dysfunction undergo an assessment of cardiovascular risk, including assessing risk factors for cardiovascular disease.
Depending on the symptoms elicited, further investigations including blood tests will be performed. These blood tests will include a check of testosterone (which is best checked first thing in the morning, preferably after fasting), as well checking other hormones, including thyroid function and blood sugar (or glycosylated haemoglobin, HbA1c, which may be used to check for diabetes).
The treatment of erectile dysfunction depends on the underlying cause. If an underlying physical cause is found (such as diabetes), treatments will be needed to manage these. Other treatments, such as cognitive behavioural therapy (CBT), may be offered for any related mental health disorders including anxiety and depression. Irrespective of the contributing causes, psychosexual counselling may be recommended to help with the effects of impotence on sexual relationships.
Erectile dysfunction itself may be treated with both medical and non-medical treatments.
First-line treatment is typically with the use of phosphodiesterase inhibitors, such as sildenafil (also known as Viagra). In the UK, Viagra is now available without a prescription, and can be obtained over the counter from pharmacists, once suitability has been assessed. A vacuum device, or pump, can also be useful especially if medications are not suitable. Vacuum pumps work by encouraging blood flow to the penis, resulting in an erection.
If these fail to improve symptoms, second-line treatments include a topical cream (alprostadil, prostaglandin E1) which works by relaxing the blood vessels, improving blood supply to the penis, and so causing an erection. Alternatively, alprostadil (prostaglandin E1) may also be injected into the penis, to relax blood vessels
More permanent surgical prostheses may be considered, but only after conservative options have been attempted.
Phosphodiesterase inhibitor medications, such as sildenafil (Viagra) can cause a reduction in blood pressure, and so should not be taken by patients known to have low blood pressure (hypotension), or in those who have recently had a stroke or heart attack. Similarly, they should not be used in patients who take nitrate medication (such as glyceryl trinitrate, GTN, or isosorbide mononitrate) for chest pain. Phosphodiesterase inhibitor medications are associated with some side-effects, which include headaches, hot flushes, and dizziness. More serious side-effects may occur less commonly, including chest pains, prolonged and painful erections (priapism) or a change in vision. If patients experience any of these symptoms, they should seek immediate medical attention.
The vacuum device is relatively well tolerated but may cause pain, bruising and numbness.
Erectile dysfunction may have a significant impact on both patients and their relationships. It therefore is important to seek appropriate help and support, both from GPs and from other organisations, such as Relate.
It is known that certain lifestyle factors can increase the likelihood of erectile dysfunction, and therefore patients may be advised to reduce their alcohol intake and stop smoking. Regular exercise may also help symptoms, as it may improve physical health, in addition to reducing any symptoms of anxiety or stress that may be contributing to the condition. However, cycling for more than 3 hours a week has been shown to increase the likelihood of erectile dysfunction, and so if patients cycle more than this, they should be advised to seek alternative means of exercise.
Last reviewed: Feb 2021