Erectile Dysfunction

  • Causes
  • Diagnosis
  • Treatment

Erectile dysfunction

Erectile dysfunction (ED) is an inability to obtain or maintain an erection that is suitable for intercourse. It is a very common condition, particularly in older men. It is estimated that half of all men between the ages of 40 and 70 will have it to some degree.


When a man becomes sexually excited (aroused), his brain sends signals to the nerves in his penis. The nerves increase the blood flow to the penis, causing the tissue to expand and harden.

Anything that interferes with the nervous system or the blood circulation to the penis can lead to erectile dysfunction. Low testosterone can affect the level of sexual desire (libido) and can also cause erectile dysfunction. Psychological conditions, such as depression, can also impact significantly on erectile function.

Alcohol and recreational drugs also affect erectile function and should be avoided to try and improve the situation.

Physical causes

There are four main types of health conditions that can cause physical problems resulting in erectile dysfunction. These are:

  • Vasculogenic - conditions affecting the flow of blood to your penis.
  • Neurogenic - conditions affecting your nervous system, which is made up of your brain, nerves and spinal cord.
  • Hormonal - conditions affecting your hormone levels. 
  • Anatomical - conditions affecting the physical structure of your penis.

Vasculogenic conditions

Examples of vasculogenic conditions that cause erectile dysfunction include:

  • Cardiovascular disease – a disease of the heart or blood vessels, such as atherosclerosis (hardening of the arteries)
  • High blood pressure (hypertension)
  • Diabetes – a condition caused by high blood sugar levels. This can affect both the blood supply and the nerve endings in the penis so it is also a neurogenic condition.

Erectile dysfunction is strongly associated with cardiovascular disease. For this reason, it may be one of the first causes your GP considers when making a diagnosis and planning your treatment.

Neurogenic conditions

Examples of neurogenic conditions that cause erectile dysfunction include:

  • Multiple sclerosis – a condition that affects the body's actions, such as movement and balance
  • Parkinson’s disease – a condition that affects the way that the brain co‑ordinates body movements including walking, talking and writing
  • A spinal injury or disorder.
  • Stroke – a serious condition that occurs when the blood supply to the brain is interrupted.

Hormonal conditions

Examples of hormonal conditions that cause erectile dysfunction include:

  • Hypogonadism – a condition that affects the production of the male sex hormone, testosterone, causing abnormally low levels.
  • An overactive thyroid gland (hyperthyroidism) – where too much thyroid hormone is produced.
  • An underactive thyroid gland (hypothyroidism) – where not enough thyroid hormone is produced.
  • Cushing's syndrome – a condition that affects the production of a hormone called cortisol.

Anatomical conditions

  • Peyronie's disease, which affects the tissue of the penis, is an example of an anatomical condition that can cause erectile dysfunction.

Medication can also cause erectile dysfunction and these include: 

  • Diuretics – these increase the production of urine and are often used to treat high blood pressure (hypertension), heart failure and kidney disease.
  • Antihypertensives – such as beta blocker, that are used to treat high blood pressure.
  • Fibrates – medicines used to lower cholesterol levels.
  • Antipsychotics – used to treat some mental health conditions, such as schizophrenia.
  • Anticonvulsants – used to treat epilepsy.
  • Anti-androgens – medication that suppresses androgens (male sex hormones).
  • Cytotoxics – medication used in chemotherapy to prevent cancer cells from dividing and growing.

Psychological causes are an extremely important cause of erectile dysfunction, they include: 

  • Depression– feelings of extreme sadness that last for a long time.
  • Anxiety– a feeling of unease, such as worry or fear.
  • Stress.
  • Relationship issues.

Erectile dysfunction usually has a mixture of both physical and psychological causes. For example, if you have diabetes, it may be difficult for you to get an erection, which may cause you to become anxious about the situation. The combination of diabetes and the anxiety may lead to even more problems.

Diagnosing erectile dysfunction

Erectile dysfunction (ED) requires a thorough history to be taken as well as a physical examination and blood tests.


  • Your symptoms
  • Your overall physical and mental health
  • Your alcohol consumption
  • Whether you take drugs
  • Whether you are currently taking any medication
  • Level of physical activity


  • Abdominal examination
  • Examination of the scrotum and penis
  • Blood pressure
  • Digital rectal examination

Blood tests

  • Hormone profile - testosterone, LH, FSH and prolactin
  • Thyroid function tests
  • Fasting glucose
  • Fasting cholesterol

Treating erectile dysfunction 

If you have erectile dysfunction (ED), treatment will depend on what is causing it.

Treating underlying conditions

If your erectile dysfunction is caused by an underlying health condition, such as heart disease or diabetes, that condition may need to be treated first. In some cases, treating the underlying cause may also help to resolve the problem.

If you are taking medication that can cause erectile dysfunction, there may be an alternative. It is important never to stop taking a prescribed medication unless you are advised to do so.

If your testosterone is low then I will refer you to an endocrinologist (a doctor who specialises in hormones) to replace it to a normal level before other treatment is started.

Lifestyle changes can have a significant impact on erectile dysfunction. These include:

  • Losing weight if you are overweight
  • Giving up smoking 
  • Reducing alcohol consumption
  • Exercising regularly 
  • Reducing stress 

As well as helping to improve your erectile dysfunction, these changes can also improve your general health and may help to reduce your risk of cardiovascular disease (conditions that affect your heart and blood vessels).

Phosphodiesterase-5 (PDE-5) inhibitors

Phosphodiesterase-5 (PDE-5) inhibitors are one of the most widely used and effective types of medication for treating erectile dysfunction. They work by temporarily increasing the blood flow to the penis.

In England, three PDE-5 inhibitors are most commonly used for treating erectile dysfunction. They are:

  • Sildenafil – sold under the brand name Viagra
  • Tadalafil – sold under the brand name Cialis
  • Vardenafil – sold under the brand name Levitra

Depending on the type of PDE-5 inhibitor you are prescribed, it should take about 30-60 minutes before it starts to work.  It may take longer to notice the effects if the tablet is taken with fatty food. Sexual stimulation is required for the tablets to help achieve an erection.  

There have been many studies to test the effectiveness of these medications. In general, at least two-thirds of men report having improved erections after taking one of these medicines.

PDE-5 inhibitors should be used with caution in men who have significant cardiovascular disease. They should not be taken in patients who are prescribed long acting nitrates. They can also cause low blood pressure and therefore should not be taken at the same time as alpha blockers as this can potentiate the effect.

Side effects include:

  • Headaches and migraines, flushing (redness), indigestion, nausea (feeling sick), vomiting (being sick), blocked or runny nose, back pain, vision disturbances and muscle pain.
  • Vacuum pumps

A vacuum pump consists of a clear plastic tube that is connected to a pump, which is either hand or battery operated.

You place the penis in the tube and pump out all of the air. This creates a vacuum that causes the blood to fill the penis, making it erect. You then place a rubber ring around the base of the penis to keep the blood in place, allowing you to maintain an erection for around 30 minutes.

It may take several attempts to learn how to use the pump correctly but they are usually effective. After using a vacuum pump, nine out of 10 men are able to have sex, regardless of the cause of their ED.


You should not use a vacuum pump if you have a bleeding disorder or if you are taking anticoagulant medicines, which reduce the ability of your blood to clot.

Side effects of vacuum pumps include pain or bruising, although these occur in less than a third of men.

Intracavernosal / intraurethral injection of prostaglandins

Alprostadil is a synthetic (man-made) hormone that helps to stimulate blood flow to the penis

Alprostadil is available as:

  • An injection directly into the penis – this is called an intracavernosal injection.
  • A small pellet placed inside the urethra (the tube that carries urine from the bladder to the tip of the penis) – this is called urethral application.

We will teach you how to use these devices in the clinic.

If your partner is pregnant, use a condom during sex if you are inserting Alprostadil into your urethra.

Alprostadil will usually produce an erection after five to 15 minutes. How long the erection lasts will depend on the dose.

In men who did not respond to PDE-5 inhibitors, Alprostadil injections are successful in 85 out of 100 men. Alprostadil inserted into the urethra is successful for up to two-thirds of men.


Alprostadil should not be used:

  • In men at risk of priapism (a painful erection that lasts for several hours), for example, those with sickle cell anaemia
  • Alongside other erectile dysfunction medications 
  • If you have a penile implant

Side effects include:

  • Changes in your blood pressure, dizziness, headache, pain in your penis, urethral burning or bleeding, reactions at the site of the injection - such as swelling and priapism.


Surgery for erectile dysfunction is usually only recommended if all other treatment methods have failed.

Penile implants are avaliable in two forms:

  • Semi-rigid implants – which may be suitable for older men who do not have sex regularly. They are easier to place and use than the inflatable prosthesis
  • Inflatable implants – which consist of two or three parts that can be inflated to give a more natural erection

Complications can include:

  • Infection
  • Erosion of the prosthesis through the skin
  • Failure - approximately 5% at 5 years
  • Need for removal

If the surgical option became necessary as all other treatemnts had failed I would refer you on to an Andrologist who specialises in this procedure. I do not offer this operation as it is extremely specialist.