Erectile dysfunction is the frequent or consistent inability to get or sustain an erection of the penis sufficient to engage in sexual intercourse. While most men occasionally fail to get an erection, or lose one prematurely during sexual activity, some men suffer from these problems regularly.
Accurate statistics are lacking on how many men are affected by the condition, but some doctors estimate that about half of men aged 40 to 70 have frequent problems achieving or maintaining an erection. The number of men with erectile dysfunction is low for those under the age of 40, but it increases with age.
A wide range of diseases, medications, injuries, and psychological problems can cause erectile dysfunction. Here are some of the most common causes:
Circulatory problems: An erection occurs when the penis fills with blood and a valve at the base of the penis traps it. Diabetes, high blood pressure, cholesterol, clots, and atherosclerosis (hardening of the arteries) can all interfere with this process. Such circulatory problems are the number one cause of erectile dysfunction.
Peyronie's disease: This disease causes fibres and plaques to appear in the genitals, interrupting blood flow.
Cancer: Cancer can interfere with nerves or arteries that are vital to erection.
Surgery: Surgery to the pelvis, and especially prostate surgery for prostate cancer, can damage the nerves and arteries that are required to gain and maintain an erection.
Spinal cord or pelvic injury: The nerves that stimulate erection can be cut by injury to them.
Hormonal disorders: A lack of testosterone (male hormone or androgen) can result from testicular failure, pituitary gland problems, or certain medications.
Depression: This condition is a common cause of erectile dysfunction. Depression is a physical disorder as well as a psychiatric one, and it can have physical effects. This may be true even if you feel comfortable in a sexual situation.
Alcoholism: Chronic alcoholism can produce erectile dysfunction, even if there is no alcohol in the blood at the time of sex.
Smoking: Smoking cigarettes causes constriction of blood vessels. This may decrease blood flow to the penis, causing erectile dysfunction.
Performance anxiety: Most men have had erection problems at some point due to worrying about performing well during sexual intercourse. If this happens often, the anticipation of sex can trigger nervous reactions that prevent erection, setting up a vicious cycle.
Situational psychological problems: Some men have problems only in certain situations or with certain people. In troubled relationships, men may be unable to achieve erection with their partner but have no problem away from home.
Sexual aversion: Being repelled by sex is rare. It is most common in people who suffered child abuse and those who have been brought up in strict religious surroundings. Aversion can also exist in homosexual or bisexual people who attempt to lead a heterosexual life against their basic inclinations.
Drugs: The following can cause erectile dysfunction:
- antianxiety medications
- anticancer medications
- ganglionic and adrenergic (beta) blockers
- MAO inhibitors and tricyclic antidepressants
- narcotic pain relievers
- medications prescribed to control high blood pressure
Symptoms and Complications
When a man is unable to get or maintain an erection, it is termed erectile dysfunction. It may also be called erectile difficulties.
A man may sometimes have erections, (e.g., when he wakes up in the morning), but be unable to get an erection during sex with his partner. This is often a sign of a psychological problem that may or may not have to do with that particular relationship.
If a man had regular erections in the past, but suddenly begins to have problems getting an erection, there's a chance that it's a nerve or hormonal problem, a circulatory problem, or the effect of alcohol, drugs, or medicine.
If a man still gets erections but they're not as hard or long lasting as in the past, it's quite likely that a circulatory problem is causing the dysfunction.
If surgery or injury is involved, the sufferer may already know what's causing the erectile dysfunction. A doctor should be consulted about possible solutions.
While erectile dysfunction is inevitably going to cause some anxiety, it's vital for sufferers to keep their relationship with their partner or spouse as regular as possible until a solution can be found. Modern medicine and therapeutic techniques can help over 90% of erection problems.
Making the Diagnosis
To find out what's causing erection problems, a doctor will begin by asking about other medical conditions the man might have, what medications he's taking, when his erection problems occur, and what form they take.
Standardized questionnaires or surveys about erectile function and the satisfaction of sexual intercourse may be used to identify the nature of erectile dysfunction. Blood pressure tests and tests of hormone levels are standard.
There are tests that aim to distinguish between psychological, nervous, and circulatory causes. One is the nocturnal penile tumescence (NPT) test. A measuring device is attached to the penis to monitor erections during sleep. Men without physical disorders usually have erections during REM (rapid eye movement) sleep.
Several devices, including a Doppler radar, can track blood flow in and out of the penis and identify circulatory problems.
Treatment and Prevention
There's a wide range of treatments for erectile dysfunction. Some are pills, and others are injections or devices that should be used just before sex. There are also treatments involving surgery.
Medications for erectile dysfunction include phosphodiesterase inhibitors, prostaglandins, and testosterone.
Phosphodiesterase inhibitors: This class of medications includes sildenafil,* tadalafil, and vardenafil. They work by inhibiting an enzyme called phosphodiesterase type 5 (PDE-5). This enzyme normally breaks down a molecule called cGMP. Inhibiting the enzyme makes more cGMP available, which leads to relaxation of smooth muscles in the penis, allowing more blood to enter and helping to produce an erection. These medications are taken before sex and will cause an erection only when the man is sexually stimulated.
The time the dose should be taken and how long the effects last depend on the medication used. The most common side effect of these medications is a headache. However, there is a potential for certain dangerous drug interactions. Anyone taking this medication must let his doctor know about any medications he's on, and especially if he's taking nitrates (e.g., nitroglycerin spray, nitroglycerin pills, or nitroglycerin patch) for heart problems.
Prostaglandins (alprostadil): Alprostadil can be injected into the penis or inserted as a pellet through the urethra. It causes an erection that usually lasts about 60 minutes. The danger with this method is that too high a dose can cause priapism, an erection that won't go away. This condition can cause serious bruising, bleeding, and pain. Once the doctor is sure of the right dose, the man can self-inject at home.
Some doctors may prescribe a combination of alprostadil with additional ingredients such as phentolamine to help the medication work more effectively. This mixture is prepared by the pharmacy according to the directions of the prescribing doctor. It is injected into the penis before sex.
Testosterone: This is only useful for people with specific disorders like hypogonadism (small testicles) that result in lower than normal amounts of testosterone in the blood stream. Testosterone increases interest in sex, as well as erections.
Common non-medication ways of treating erectile dysfunction include vacuum devices and penile implants.
Vacuum devices: This involves placing a tube over the penis, forming an airtight seal around the base. By pumping air out of the tube, blood can be drawn into the penis. Placing a ring around the base of the penis will maintain the erection.
Penile implants: This treatment involves permanent implantation of flexible rods or similar devices into the penis. Simple versions have the disadvantage of giving the user a permanent erection. The latest (and most expensive) device consists of inflatable rods activated by a tiny pump and switch in the scrotum. Squeezing the scrotum stiffens the penis, whether the person is aroused or not. The penis itself remains flaccid, however, so the diameter and length are usually less than a natural erection, and hardness is lacking, although it's sufficient for intercourse.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.