Erectile Dysfunction (Impotence)
Erectile dysfunction (ED) means that you cannot get and/or maintain an erection. In some cases the penis becomes partly erect, but not hard enough to have sex properly. In some cases, there is no swelling or fullness of the penis at all. ED is sometimes called impotence.
Most men have occasional times when they cannot get an erection. For example, you may not get an erection so easily if you are tired, stressed, distracted, or have drunk too much alcohol. For most men it is only temporary, and an erection occurs most times when you are sexually aroused. However, some men have persistent, or recurring, ED. It can occur at any age, but becomes more common with increasing age. About half of men between the ages of 40 and 70 have ED.
How does an erection normally occur?
When you are sexually aroused, messages from your brain travel down nerves to your penis. Chemicals called neurotransmitters are then released from the ends of the nerves in the penis. Stimulation of the penis can also cause local nerve endings to release neurotransmitter chemicals. The neurotransmitters which are released in the penis cause another chemical to be made called cyclic guanosine monophosphate (cGMP). An increase of cGMP causes the arteries in the penis to dilate. This allows extra blood to flood into the penis. The rapid inflow of blood causes the penis to swell into an erection. The swollen inner part of the penis also presses on the veins nearer to the skin surface of the penis. These veins normally drain the penis of blood. So, the flow of blood out of the penis is also restricted, which enhances the erection.
The cGMP is soon converted into another inactive chemical. But, as you remain sexually aroused whilst having sex, your brain keeps sending nerve messages to the penis which makes more cGMP to maintain the erection. When the level of cGMP falls, the blood flow to the penis returns to normal, and the penis gradually returns to the non-erect state.
What causes erectile dysfunction?
- Reduced blood flow to the penis. This is, by far, the most common cause of ED in men over the age of 40. Risk factors can increase your chance of narrowing of the arteries. These include: getting older; high blood pressure; high cholesterol; smoking; diabetes.
- Diseases which affect the nerves going to the penis. For example, multiple sclerosis, a stroke, Parkinson's disease, etc.
- Hormonal causes. For example, a lack of a hormone called testosterone which is made in the testes.
- Injury to the nerves going to the penis. For example, spinal injury, following surgery to nearby structures, fractured pelvis, radiotherapy to the genital area, etc.
- Side-effect of certain medicines. The most common are: some antidepressants; betablockers such as propranolol, atenolol.
- Alcohol and drug abuse.
- Cycling. ED after long distance cycling is thought to be common.
Mental heath (psychological) causes
- Relationship difficulties.
Erectile dysfunction, heart disease and other vascular diseases
Although ED can be caused by various conditions, about 7 in 10 cases are due to narrowing of the small arteries in the penis. This causes reduced blood flow to the penis. The root cause of the narrowing of the arteries is caused by atheroma. Atheroma is like fatty patches or plaques that develop within the inside lining of arteries.
Certain risk factors increase the risk of more atheroma forming which can make atheroma-related conditions worse.
- Smoking. Smoking is one of the biggest risk factors for developing an atheroma-related condition.
- High blood pressure.
- If you are overweight.
- A high cholesterol.
- Alcohol excess.
What should I do if I develop persistent erectile dysfunction?
It is best to see your doctor. He or she is likely to discuss the problem, go over any medication you may be taking, and do a physical examination. This can help to identify, or rule out, possible underlying causes.
What tests may be done?
Tests may include:
- A blood test to check the level of cholesterol and other lipids (fats).
- Blood sugar level.
- Blood tests to rule out kidney and liver disease.
- A urine test.
- A check of your blood pressure.
- A heart tracing (ECG).
- If you have low sex drive, or if you have had a previous head injury, ED may be due to a hormonal problem. In this situation a blood test to check the level of the hormone testosterone (and sometimes prolactin) may be advised.
What are the treatment options?
A referral to a specialist is sometimes needed for assessment and treatment.
Medication (tablets taken by mouth)
Some of the tablets work by increasing the blood flow to your penis. They do this by affecting cGMP, the chemical involved in dilating (widening) the blood vessels when you are sexually aroused. They are sildenafil (trade name Viagra®), tadalafil (trade name Cialis®), and vardenafil (trade name Levitra®). You take a dose before you plan to have sex. Because of the way they work, these medicines are called phosphodiesterase type 5 (PDE5) inhibitors.
Apomorphine (trade name Uprima®) works by increasing the level of certain chemicals in the brain which are involved in sending messages down nerves to the penis when you are sexually aroused. You take a tablet, which dissolves under the tongue, 20 minutes before you plan to have sex.
There is a good chance that a medicine will work (about an 8 in 10 chance of it working well). However, they do not work in every case.
Pelvic floor muscle exercises
A common treatment for incontinence in women is to strengthen the pelvic floor exercises. Some studies suggest that strengthening the pelvic floor muscles in men can cure ED in some cases.
For example, one study found that after a course of pelvic floor exercises, about 4 in 10 men with ED had regained normal erectile function. The exercises were done for a time every day for three months.
To identify your pelvic floor muscles: firstly, contract the muscles that you would use to stop passing wind from your anus; secondly contract the muscles that you would use to stop the flow of urine. These are the muscles that can be trained and strengthened.
This was the most common treatment before tablets became available. It usually works very well. You are taught how to inject a medicine into the base of the penis. This causes increased blood flow, and an erection usually develops within 15 minutes. (Unlike with tablets, the erection occurs whether of not you are sexually aroused.)
You can place a small pellet into the end of the urethra (the tube which passes urine and opens at the end of the penis). The pellet contains a similar medicine to that used for the injection treatment. The medicine is quickly absorbed into the penis to cause an erection, usually within 10-15 minutes.
There are several different devices. Basically, you put your penis into a plastic container. A pump then sucks out the air from the container to create a vacuum. This causes blood to be drawn into the penis and cause an erection. When erect, a rubber band is placed at the base of the penis to maintain the erection. The plastic container is then taken off the penis and the penis remains erect until the rubber band is removed (which must be removed within 30 minutes).
A surgeon can insert a rod permanently into the penis. The most sophisticated (expensive) type can be inflated with an inbuilt pump to cause an erection. The more basic type keeps the penis rigid all the time.
Treating an underlying cause
For example, treating depression, anxiety, changing medication, cutting back on drinking lots of alcohol, or treating certain hormonal conditions may cure the associated ED.
Lifestyle and other advice
For example, stop smoking if you are a smoker, take regular exercise, eat a healthy diet, etc. Also, your doctor may prescribe a statin drug to lower your blood cholesterol level if your risk of developing cardiovascular disease is high.
Sometimes couple counselling, or sex therapy is useful. These are most useful if certain psychological problems are the cause of, or the result of, ED.
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