The reasons behind erectile dysfunction

Written by the Manual Team · Medically approved by Dr Earim Chaudry - MD

In 30 seconds

What is erectile dysfunction (ED)? Erectile dysfunction is the inability to maintain or sustain an erection satisfactorily enough for sexual intercourse. This presents in many forms and is personal to each individual. One may get an erection briefly and then lose firmness, fail to achieve an erection at all, or get an erection, maintain it for a while and then lose it during sexual intercourse. 

Why does erectile dysfunction happen? Erectile dysfunction has many functional causes broadly defined as physiological, physical or psychological causes. But the general physiological dysfunction results from low blood flow to the penis or a problem with the nerves that control erections. Low levels of testosterone may also cause ED

Is erectile dysfunction normal? Erectile dysfunction is not a normal state, but it is very common. While men may have occasional or situational erection difficulties, caused by too much drinking, performance anxiety or acute stress, it is not normal for erection problems to occur on a regular basis. As men get older, erections may become slightly less firm and last a shorter time than for younger men but this isn’t always the case. ED is not inevitable in older men and a doctor should always be consulted.

How does an erection work?

A healthy erection results in a firm, rigid penis which enables a man to have sexual intercourse or engage in masturbation to the point of orgasm. If enough firmness isn’t attained this is not possible. When a man becomes sexually excited (either by manual stimulation or emotional and hormonal stimulus), the arteries within the penis relax and expand. This allows more blood to flow into the penis.

The veins inside the penis close at the same time. Now that the penis is filled with blood, pressure keeps it within two cylindrical areas called the corpora cavernosa. At this stage your penis expands and becomes erect. When the flow of blood into the penis stops and the veins open, your penis softens.

The two cylinders (corpora cavernosa) are critical in obtaining and maintaining an erection and the blood flow and pressure within these cavities determines how rigid an erection will be. Because of this, anything which affects the amount of blood within the cavity or the amount of pressure maintained within, will, in turn, affect the strength and quality of an erection.


How does erectile dysfunction happen?

The little blue pill

It's the active ingredient in Viagra. Clinically proven to be highly effective in helping you get and keep an erection by increasing blood flow to the penis. Easier erections, happy days.
Start from £15

Erections may show themselves physically, but they begin in the brain. When the mind or body is sexually stimulated, a brain chemical called nitric oxide is released. This is a chemical messenger that causes smooth muscle enzymes to produce other chemicals. These chemical messengers increase the size of blood vessels that flow into the penis and constricts the outflow of blood from the penis. Any illness or disorder which affects this process will cause erectile dysfunction.

ED is very common and affects about 4.3 million men in the UK or 1 in 5. Since it’s so common and has a significant impact on men’s health and relationships, it has been intensively studied by doctors and scientists. This means that there are very effective treatment options available, no matter the cause.

Common health problems like heart disease (atherosclerosis), obesity, diabetes, high cholesterol, lifestyle factors and mental illness are also well understood. Working with this knowledge, doctors are usually able to treat and alleviate ED.


What are the symptoms of erectile dysfunction?

The weekend pill

It's the active ingredient in Cialis. Known as the "weekend pill" for its long lasting effects, it's clinically proven to help you get an erection when you need it - for up to 36 hours!
Start from £15

The first sign that something is wrong is usually the inability to get an erection, or to sustain firmness. However, some men may be able to get an erection, but lose it quickly and are, thus, not able to enjoy sexual intercourse. Erections may gradually or rapidly become inconsistent. In this case, you may sometimes sustain a healthy erection followed by occasions where you can’t. Symptoms may remain stable or worsen over time. 


What are the reasons for erectile dysfunction?

There are many factors which can cause erectile dysfunction, ranging from physical illnesses and low levels of testosterone to psychological factors like depression and anxiety. Erection problems may also be triggered by lifestyle choices like smoking, drug and alcohol abuse, regular cycling for fitness and sport or prescription medication.

Erectile dysfunction is the result of insufficient blood flow into the penis and/or insufficient pressure inside the penis. Poor blood flow does not fill the tissues inside the penis and low internal pressures mean an erection cannot occur, or occur with enough firmness to engage in sexual intercourse. Or it may occur briefly and then be lost. 

Erectile dysfunction reasons include diabetes, high blood pressure, high cholesterol and hardening of the arteries. Metabolic syndrome and Parkinson’s disease cause a variety of effects on the nerves in the body and can lead to nerve damage. When the nerves and blood vessels that control the supply of blood to the penis become dysfunctional or damaged, the loss of stimulus can result in erection problems.