What Causes Erectile Dysfunction

Erectile dysfunction can be regarded as a condition that can affect a man’s quality of life.

Quality of life is not only defined as the basic health of an individual that helps him walk properly and do the daily chores of life. Quality of life is also defined as the overall health and well-being of a person and also generally how happy he/she is with their lives, and how satisfying lives are they leading.


If a man’s quality of relationship with his partner is affected it, in turn, affects his quality of life.


To not have a healthy sexual relationship in marriage etc. can take its toll on a man’s mental health in turn affecting his self-esteem, confidence etc. A healthy sexual relationship with your partner does uplift a relationship/marriage in a very positive way and is even a marker of a good relationship. In fact, some marriage coaches recommend a recipe for a happy long-term marriage that includes great verbal communication, trust in each other and a passionate sex.

But unfortunately for some men, erectile dysfunction plagues the fun out of their lives. It is not considered as a normal condition at any age in a man’s life. Although the phenomenon is more common in older men it is not seen as a normal sign of aging. Let’s see what this condition really is. What are its causes, and how can we get rid of it.


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Define Erectile Dysfunction

Erectile dysfunction, commonly referred to as ED, or impotence, is the inability to achieve and sustain an erection sufficient for satisfactory sexual intercourse. Erectile dysfunction is a condition where man finds it persistently hard to achieve a satisfactory erection and it interferes with sexual performance. In a normal body mechanism, usually during arousal blood flushes to the groin area and fills up the penis, as a result, an erection is achieved.

When men become sexually aroused, hormones, muscles, nerves, and blood vessels all work with one another to create an erection. Nerve signals, sent from the brain to the penis, stimulate muscles to relax. This, in turn, allows blood to flow to the tissue in the penis. Once the blood fills the penis and an erection is achieved, the blood vessels to the penis close off so that the erection is maintained. Following sexual arousal, the veins to the penis again open up, allowing the blood to leave.

This complex but normal body mechanism is controlled by a network of blood vessels and nerves. But for various reasons men, all of a sudden fail to achieve this erection and as a result erectile dysfunction happens. But What causes erectile dysfunction? Impotence is broadly categorised into two classes.

  • Primary erectile dysfunction or Organic impotence
  • Secondary erectile dysfunction or Psychogenic impotence

Let’s see these classes in detail and get to the root of the problem! Starting with primary causes of erectile dysfunction.




Organic impotence or primary impotence is referred to as an erectile dysfunction that is more physical in nature. To put it in simple words it means that it is a dysfunction caused by physical changes in the body.  An erection happens naturally when the blood flows to the penis during sexual arousal. If due to the restriction of these blood vessels the blood doesn’t reach the groin area then the dysfunction that happens is referred to as Organic in nature. But problems in blood circulation is just one reason of primary erectile dysfunction. There are many other physical conditions and diseases that can cause or aggravate the condition. Let’s explore in detail the physical conditions that can result in E.D.


Physical conditions that cause erectile dysfunction;

  • Decreased blood supply to the penis


As we have already seen before for an erection to occur, a series of events must take place. The first event is a psychosexual stimulation. This is usually controlled by male sex drive, known as libido. The mind then sends impulses down the nerve pathways to the penis. These nerve impulses relax the smooth muscles of the arteries which supply the penis with blood. This muscle relaxation leads to engorgement and erection of the penis. After orgasm, the blood is returned to the general circulation and the penis returns to a soft (flaccid) state. Even a minor disturbance in any of these steps such as decreased blood supply, disturbances of nerve mechanisms or psychosexual problems may lead to erection problems.


A decreased blood flow to the groin will affect the quality of erections and may cause weaker erections. Some of the reasons behind a decreased blood flow can be;

  1. Smoking
  2. Alcohol
  3. Obesity, an increased weight and fat content in the body will decrease blood circulation
  4. Sedentary lifestyle, inactivity is like new smoking of this era. It is also considered as the fourth risk factor that contributes to mortality rates all over the world.
  5. Tumour, a tumour in the groin area can also cause dysfunction.
  6. Cycling (if cycling is done more than three hours in a day)
  7. Prostate cancer




  • Low testosterone
  • High estrogen (a female hormone)


Testosterone is the main hormone responsible for all the sexual activity and characteristics in men. Low testosterone in males can result in low libido that in turn result in a lack of erection. A hormonal imbalance in the body such as low testosterone and high prolactin combined with abnormal thyroid levels can cause E.D.


Testosterone is the main hormone in male body responsible for erections. It is the hormone that gives men their libido and they feel that bust of youthfulness and vitality. Erectile dysfunction most of the times is a sign that testosterone levels in the body are not at their healthy levels. A healthy level of testosterone in the body is indicated by morning erections. If a man is getting morning erections at the time he wakes up from sleep then that means that his testosterone levels are at an optimal level.


Nowadays an average male of 40 years has testosterone levels in his body that a 70 years old man had approx. 50 years ago.

Testosterone in modern day’s man is decreasing and the reason being are the Xeno-esterogens that we are exposed to. Estrogens are present in pesticides sprayed on food, in the water that we drink, in the plastic containers that we eat in. Our environment is full of estrogens.


A hormonal imbalance in male’s body happens when body is exposed to a lot of estrogens. This results in a rise in estrogen hormone in male body, this signals the brain to stop making testosterone, low testosterone level results in higher estrogen, high esterogen stores fat in the belly ( fat is always stored in belly in men), this produces high amounts of free radicles that damage veins, and puts men to a risk of heart attacks.


So having a low testosterone level in a male body can be dangerous for him not only in terms of having a sexual dysfunction but also puts him at an increased risk of a heart attack.

Now a question may arise, what to do about it? How to boost testosterone levels?

Well, my honest suggestion would be to never take hormones from outside source, male body is designed to make hormones and not take it from outside. Hormones from outside work for some time and then the body stops responding to them. There are certain testosterone boosting diets and herbs that can be taken. They are free of side effects as well. Adding essential minerals to your diet like zinc, selenium, chromium also help to relieve the condition.


  • Parkinson’s disease


Although Parkinson’s disease is not characterized as a hormonal disorder, it is a neurological disorder. It is a movement disorder and usually worsens over a period of time. We are mentioning it here because Dopamine is a hormone responsible for Parkinson’s disease. There is a correlation between three hormones in a male’s body. Prolactin, testosterone and dopamine.

Usually, when the testosterone levels are low, prolactin levels are increased and when prolactin is increased as a result dopamine is decreased. And decreased dopamine causes Parkinson’s.

Although not a direct link, usually patients that have Parkinson’s disease also complain about erectile dysfunction because they have low testosterone in their body coupled with other motor dysfunctions and the GP makes sure that he manages the condition for the patient.




Our cardio vascular system is made up of heart, arteries and veins of the body. We know that a plane cannot take off without a fully functioning engine. The heart is like an engine too and if it’s not working at an optimized level it can result in E.D. Sometimes a sexual dysfunction is actually due to an underlying heart disease. As our heart controls the blood supply to the whole body therefore any issue with blood supply can result in nil or minimum erection.

Blood capillaries that supply blood to the penis are very miniscule in size. Any damage to them or decreased blood flow to this area can, unfortunately, result in a permanent impotence.


  • Atherosclerosis


Atherosclerosis is a condition in which cholesterol deposits into the arteries and results in narrowing of the arteries. This narrowing of blood vessels is called as endothelial dysfunction and it is the first stage of atherosclerosis. The cholesterol forms a plague within the arteries and narrows them thereby stopping the blood flow completely and causing heart attacks.

Endothelial dysfunction prevents the blood vessels from dilating properly as a result blood flow is slowed down or blocked depending upon the condition.  When the blood vessels that supply the penis are not able to dilate during sexual stimulation because of endothelial dysfunction, the penis cannot fill with blood, and the man develops erectile dysfunction. As atherosclerosis progresses, plaques build up in blood vessels and blood flow is slowed, further worsening erectile function7.

Atherosclerosis can affect different vital organs of the body. The affected organ depends upon the person, his age, and how much the condition has been progressed/worsened. But it is often seen that it affects penis first, then brain and heart and legs are often affected at the last. Erectile dysfunction, in this case, is like a warning sign that this person is pre disposed to a heart attack or stroke in a few years of time. This warning sign can be a good thing if it alerts the doctor, and he can diagnose the underlying endothelial dysfunction, and as a result, a heart attack or stroke can be prevented in long run.


  • Hypertension


Hypertension causes changes in the endothelial layer of the blood vessels and causes them to lose their elasticity. Due to chronic high B.P. the blood vessels harden. As the blood vessels harden and lose their elasticity it gets difficult for them to dilate and as a result blood flow is slowed down. This slowed blood supply to the penis sometime causes erectile dysfunction.  Hypertension may affect the veins, allowing the blood that  rush into the penis to exit quickly. The effects of hypertension on erectile function are cumulative over time and may occur even before a man knows he has hypertension.


Some anti-hypertensive medicines can also cause erectile dysfunction. Medications like Diuretics (water tablets) and beta blockers can cause this problem but it usually doesn’t happen to everyone. If you are taking any of these medications and are worried about erectile dysfunction consult your GP and he may be able to make changes to your medication




Diabetes is a condition in which the blood glucose (sugar) levels become too high. The glucose doesn’t get metabolised (reach the cells for breakdown) and starts accumulating in the blood. Insulin is a hormone produced by the pancreases, is necessary to take the glucose to the cells for the breakdown. It acts as a transporter. If sufficient insulin is not produced within the body then sugar start accumulating in the blood and causes diabetes.


Diabetes has many complications in the body. We won’t discuss it in detail but the most common complication is Neuropathy. Neuropathy, in simple words, can be defined as damage to the nerves. Over a long period of time diabetes cause a lot of damage to the nerves of hands, feet and in other parts of the body. Neuropathy can also affect penis and as a result erectile dysfunction happens.


A scientific study shows that erectile dysfunction is more associated with atherosclerosis and could be used as an indicator of heart or brain disease (coronary or cerebrovascular disease) 10.


Diabetes is often referred to as a disease due to lifestyle. Obesity and a sedentary lifestyle are the main cause of diabetes. According to a recent research, obesity is termed as the fourth cause of mortality worldwide after smoking. It also puts the body at high risk of cancer.



Although to study all the neurological disorders in depth is out of the scope of this article but generally neurological disorders cause erectile dysfunction by weakening the nerves that carry out motor activities in the body. Sometimes erectile dysfunction is a manifestation of other conditions happening in the body. Some of the neurological disorders that cause E.D. are;

  • Alzheimer’s disease
  • Multiple sclerosis
  • Parkinson’s disease
  • Epilepsy
  • Tumours

We have seen Organic/primary impotence and its causes in detail. Let’s now have a quick look at secondary erectile dysfunction.




Psychogenic erectile dysfunction is defined as the persistent inability to achieve or maintain an erection satisfactory for sexual performance owing predominantly or exclusively to psychologic or interpersonal factors.11.  ED due to psychological factors is referred to as psychogenic impotence and is usually due to anxiety, guilt, low self-image etc.

Erectile dysfunction caused by psychological factors is secondary E.D. It is a condition where a man experiences normal sleep and morning erections but is unable to have an erection during intercourse.


It is usually a frequent type of impotence in young men. Usually before the age of 40 sexual dysfunction rarely happens due to high B.P. or cholesterol or obesity etc. The effect of these factors usually takes longer to affect the blood vessels and blood flow in the body consequently decreasing the sexual function. Let’s see the factors that can cause this transient and sporadic E.D.


  • Depression / Anxiety


Depression, anxiety and stress can manifest itself in different forms. Unlike anxiety and stress, depression is in itself a condition that requires medication and treatment. The secondary manifestation of depression can show itself as a low libido, lack of sexual pleasure, and in turn an inability to have sex.


Similarly stresses at work, job, and relationships can affect brain sections that deal with pleasure and arousal. When the brain is dealing with stress or is in a state of chronic stress it becomes harder to focus on coitus or sex.


Sometimes certain medications for depression can also cause impotence.

In this case, doctors can recommend Behavioural cognitive therapy combined with sex therapy to deal with the problem.


  • Addictions


Medication abuse, drug abuse, and even pornography have known to cause secondary erectile dysfunction. Alcohol at low doses is known to cause sexual arousal but indulging in too much alcohol can also cause temporary impotence


Drugs like heroine, ecstasy, cocaine can cause various changes to sexual function from difficulty in achieving an erection to delayed ejaculation times. These drugs can sometimes even give painful erections. Chronic use of drugs can cause many chemical imbalances in the brain that can, in turn, interfere with sexual activity.


  • Problems with self-image, guilt, confidence etc.
  • Too much heavy or strenuous exercise and lack of rest


This kind of E.D. is usually transient in nature and is more due to low levels of testosterone in the body. When a person indulges in too many heavy forms of exercise or body building etc., they are basically using up all the stores of testosterone in the body. It is important that a man have at least 30 minutes of rest during the day. This helps up in rebuilding the testosterone stores in the body.



How to distinguish whether a person has Primary or secondary impotence:

There are certain tests that can tell us the cause behind E.D.


Hormone levels:

A simple blood test can tell us the abnormal hormonal imbalance in the body. The doctor can carry out further investigations and proper treatment may be started.


Sleep studies:

An average man at night usually gets erections about three to four times while he is unaware of it. This erection ranges from just fullness to a complete erection. Men with psychological erection problems will usually get a good strong erection lasting 10 minutes or more during sleep. Men with circulatory or other physical problems may get only partial erections and/or erections of very short duration. Some patients with severe problems may not get any erections at all. The presence or absence of these night-time erections gives the doctor valuable information about erectile dysfunction. Most sleep studies are done with a small monitor that is taken home for two nights and returned to the clinic.13


Treatment for E.D.

  • Oral medication: Viagra, Tadalafil, Spedra, Levitra, etc.
  • Medications injected into the penis
  • Hormonal therapy
  • Life style changes; quitting a sedentary life style, smoking etc.
  • Quitting alcohol
  • More exercise
  • Proper rest; helps build up testosterone
  • Taking essential minerals like zinc, selenium, chromium


The differences between the different oral medications are discussed here, while the safety of buying them online is explained in this article. 


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How does Viagra and Sildenafil work?

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You should take Viagra (Sildenafil) approximately 1 hour before planning to have intercourse. Within a window of between 30 minutes and 4 hours after you take the medicine, it will be easier to keep and maintain an erection when you are sexually excited. If you take this medicine after a meal with a high fat content it may take a little longer to start working. This medicine will only work when you are sexually excited. You won’t get an erection just by taking Viagra (Sildenafil).


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If the 100mg strength doesn’t work for you, there may be alternatives you can try and we recommend that you call us for a free consultation with our pharmacist or doctor to discuss any underlying conditions you may have. We recommend that all men taking medicine for erectile dysfunction have regular tests for blood pressure, cholesterol, diabetes and hormone imbalances. For instance, it may be that by fixing a hormone imbalance such as testosterone, your Viagra medication will be even more effective.

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It is important that you choose the correct dose for you. If you wish to talk to our pharmacist or doctor about this, please contact us in the pharmacy on 01625 460621 or email [email protected]rmacy.co.uk.

Side Effects

Viagra (Sildenafil) is normally well tolerated, however, side effects can include:

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Side effects normally subside after a few hours, however, if you experience a prolonged or painful erection (longer than 4 hours), then you must contact your doctor immediately.

Drug interactions

There are a number of medicines which interact with Sildenafil/ Viagra. For an exhaustive list please see the patient information leaflet (see section below) or call us in the pharmacy to discuss your specific situation. The main drug interactions are listed here:

Recreational drugs such as ‘poppers’ or amyl nitrate
Alpha blockers used for urinary retention or blood pressure problems (eg Flomax or Cardura)
Anti- arrhythmic drugs such as disopyramide
Antibiotics such as erythromycin
Antifungals such as itraconazole
Antivirals such as drugs used to treat HIV
Calcium channel blockers to treat blood pressure and angina such as amlodipine
Dapoxetine (Priligy – used to treat premature ejaculation)
Grapefruit juice**
Cimetidine (to treat stomach ulcers)

Please do not take Sildenafil/Viagra if you have taken any of the above drugs within the last 60 days without first consulting with either us in the Pharmacy ([email protected] / 01625 460621) or via email with our doctor [email protected]

**We advise not to take Sildenafil/Viagra with grapefruit juice as the blood concentration of Sildenafil will possibly be increased resulting in side effects.

Patient Information Leaflets

Please click here for the patient information leaflet for Viagra.

For Actavis Sildenafil please see the following leaflets: 100mg, 50mg, 25mg.

Storing Medicines Safely

Please keep your medicine out of the reach of children and store at room temperature.  Unwanted medicine can be disposed of by returning it to any local pharmacy or indeed to us here for us to dispose of it for you.

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Reference table
1 https://www.webmd.com/erectile-dysfunction/guide/erectile-dysfunction-basics 
2 https://www.healthline.com/health/erection-problems#modal-close 
3 https://www.ncbi.nlm.nih.gov/books/NBK297 
4 https://urology.med.wayne.edu/impotence-sexual 
5 https://www.treated.com/erectile-dysfunction/psychological-causes-of-ed 
6 John Gray, Men’s sexual health. https://www.marsvenus.com/blog/john-gray/erectile-dysfunction-hard-facts-about-the-soft-truth 
7 http://circ.ahajournals.org/content/123/21/e609 
8 https://urology.med.wayne.edu, Information on hypertension and impotence 
9 http://www.bloodpressureuk.org/BloodPressureandyou/Yourbody/Erectiledysfunction 
10 https://www.nhs.uk/news/heart-and-lungs/erectile-dysfunction-and-diabetes/ 
11 http://www.urologic.theclinics.com/article/S0094-0143(05)70137-3/abstract 
12 https://www.treated.com/erectile-dysfunction/psychological-causes-of-ed 
13 https://urology.med.wayne.edu , diagnostic testing on E.D. 

Assured Pharmacy is not liable for the currency or accuracy of the information contained in this blog post. For specific information about your personal medical condition, please contact our doctors or pharmacists for advice on [email protected]