Reviewed by Varnada Karriem-Norwood, MD on April 16, 2012Varnada Karriem-Norwood, MD A Visual Guide to Erectile Dysfunction

What Is Erectile Dysfunction (ED)? Erectile dysfunction (ED) occurs when a man has consistent and repeated problems sustaining an erection. Without treatment, ED can make sexual intercourse difficult. According to the Massachusetts Male Aging Study on sexual dysfunction, the problem can first emerge in a man as early as 40. Based on the study, an estimated million men are affected by ED.

ED vs. Poor Libido There are several forms of male sexual dysfunction, including poor libido and problems with ejaculation. But ED refers specifically to problems achieving or maintaining an erection. Men with ED often have a healthy libido, yet the body fails to respond. In most cases, there is a physical basis for the problem.

Symptoms of ED Symptoms of ED include: Erections that are too soft for sexual intercourse. Erections that last only briefly. An inability to achieve erections. Men who cannot get or maintain an erection (75% of the time that they attempt sex ) are considered to have erectile dysfunction.

Who Gets ED? Sexual dysfunction and ED become more common as men age. According to the Massachusetts Male Aging Study, about 40% of men experience some degree of ED at age 40 compared with 70% of men at age 70. And the percentage of complete ED increases from 5% to 15% as age increases from 40 to 70 years. But this does not mean growing older is the end of your sex life. ED can be treated at any age.

The Mechanics of ED An erection occurs when blood fills two chambers known as the corpora cavernosa. This causes the penis to expand and stiffen, much like a balloon as it is filled with water. The process is triggered by impulses from the brain and genital nerves. Anything that blocks these impulses or restricts blood flow to the penis can result in ED.

Causes of ED: Chronic Disease The link between chronic disease and ED is most striking for diabetes. Nearly one out of every two men with diabetes experiences ED. Yet evidence shows that good blood sugar control can minimize this risk. Other conditions that may cause ED include cardiovascular disease, atherosclerosis (hardening of the arteries), kidney disease, and multiple sclerosis. These illnesses can impair blood flow or nerve impulses throughout the body.

Causes of ED: Lifestyle Lifestyle choices that impair blood circulation can contribute to ED. Smoking, excessive drinking, and drug abuse may damage the blood vessels and reduce blood flow to the penis. Smoking makes men with atherosclerosis particularly vulnerable to ED. Smokers have almost twice the risks of ED compared with nonsmokers. Being overweight and getting too little exercise also contribute to ED. Studies indicate that men who exercise regularly have a lower risk of ED.

Causes of ED: Surgery Surgery, including treatments for prostate cancer, bladder cancer, or BPH can sometimes damage nerves and blood vessels near the penis. In some cases, the nerve damage is permanent, and the patient will require treatment to achieve an erection. In others, surgery causes temporary ED that improves on its own after 6 to 18 months.

Causes of ED: Medication ED may be a side effect of medication, including certain blood pressure drugs, antidepressants, and tranquilizers. Men should talk with their doctor if they suspect a prescription or over-the-counter drug may be causing erectile problems.

Causes of ED: Psychological ED usually has something physical behind it, particularly in older men. But psychological factors may be to blame in 10% to 20% of men with ED. Experts say stress, depression, poor self-esteem, and performance anxiety can short- circuit the process that leads to an erection. These factors can also make the problem worse in men whose ED stems from something physical.

ED and Bicycling Research suggests avid cyclists suffer more ED than other athletes. The trouble lies in the shape of some bicycle seats that put pressure on the perineum. This area between the anus and scrotum contains arteries and nerves vital to sexual arousal. Cyclists who ride for many hours each week may benefit from seats designed to protect the perineum.

Diagnosing ED: Physical Exam To diagnose ED, your doctor will ask you questions about your symptoms and medical history. The doctor will conduct a complete physical exam to uncover signs such as poor circulation or nerve trouble. And your physician will look for abnormalities of the genital area that could cause problems with erections.

Diagnosing ED: Lab Tests Several lab tests can help diagnose male sexual problems. Measuring testosterone levels can determine whether there is a hormonal imbalance, which is often linked to decreased desire. Blood cell counts, cholesterol levels, and liver function tests can reveal medical conditions that may account for ED.

ED: A Sign of Heart Disease? In some cases, ED can be a warning sign of more serious disease. A 2010 study suggests ED is a strong predictor of heart attack, stroke, and death from cardiovascular disease. The researchers say all men diagnosed with ED should be evaluated for cardiovascular disease. This does not mean every man with ED will develop heart disease, or that every man with heart disease has ED, but patients should be aware of the link.

Treating ED: Lifestyle Changes Many men with ED are able to improve sexual function by making a few lifestyle changes. Giving up smoking, losing weight, and exercising more often can help by improving blood flow. If you suspect a medication could be contributing to ED, talk to your doctor about adjusting your dosage or switching to another option.

Treating ED: Oral Medications You’ve probably heard of Viagra, but it’s not the only pill for ED. This class of drugs also includes Cialis, Levitra, Staxyn, and Stendra. All work by improving blood flow to the penis during arousal. They're generally taken minutes before sexual activity and should not be used more than once a day. Cialis can be taken up to 36 hours before sexual activity and also comes in a lower, daily dose. Staxyn dissolves in the mouth. All require an OK from your doctor first for safety.

Treating ED: Injections While pills for ED are convenient, some men sustain stronger erections by injecting medication directly into the penis. Drugs approved for this purpose work by widening the blood vessels, causing the penis to become engorged with blood. Another option is inserting a medicated pellet into the urethra. The pellet can trigger an erection within 10 minutes.

Treating ED: Vacuum Devices (Pumps) Vacuum devices for ED, also called pumps, offer an alternative to medication. The penis is placed inside a cylinder. A pump draws air out of the cylinder, creating a partial vacuum around the penis. This causes it to fill with blood, leading to an erection. An elastic band worn around the base of the penis maintains the erection during intercourse.

Treating ED: Surgery If ED is caused by a blockage in an artery leading to the penis, surgery can often restore blood flow. Good candidates are typically younger men whose blockage stems from an injury to the crotch or pelvis. The procedure is not recommended for older men with widespread narrowing of the arteries.

Treating ED: Implants In men with persistent ED, a penile implant can restore sexual function. An inflatable implant uses two cylinders that are surgically placed inside the penis. When an erection is desired, the man uses a pump to fill the cylinders with pressurized fluid. Another option is a malleable implant, which bolsters erections with surgically implanted rods.

Treating ED: Psychotherapy Even when ED has a known physical cause, psychotherapy can be beneficial. A therapist can teach the man and his partner techniques to reduce performance anxiety and improve intimacy. Therapy can also help couples adjust to the use of vacuum devices and implants.

Treating ED: Alternative Therapies Talk with your doctor before trying supplements for ED. They can contain 10 or more ingredients and may complicate other health conditions. Asian ginseng and ginkgo biloba (seen here) are popular, but there isn't a lot of good research on their effectiveness. Some men find that taking a DHEA supplement improves their ability to have an erection. Unfortunately, the long-term safety of DHEA supplements is unknown. Most doctors do not recommend using it.

Treating ED: Buyer Beware A quick web search will reveal dozens of "dietary supplements" that claim to treat ED. But the FDA warns that many of these are not what they seem. An investigation discovered the pills often contain prescription drugs not listed on the label, including the active ingredient in Viagra. This puts the man at risk for dangerous drug interactions.

ED: Reducing Your Risk Some tips to reduce your risk of ED include: Exercise and maintain a healthy weight. Stop smoking. Avoid alcohol and substance abuse. Keep your diabetes under control.

Discussing ED With Your Partner It's natural to feel angry or embarrassed when dealing with ED. But don't forget that your partner is also affected. Talking openly about ED will help your partner understand the diagnosis and treatment options. This will reassure your partner that you haven't lost interest.