Erectile dysfunction (ED), sometimes called impotence, is the inability to get or keep an erection firm enough for sexual intercourse. The condition has become highly visible in recent years, but that doesn’t make it any more welcome for the 5 to 15 percent of American men whose sex lives are affected.
The disorder can occur at any age, but is more common in men over age 75, according to the American Academy of Family Physicians (AAFP). In middle aged men, ED can signal risk of a heart attack, said Dr. David Samadi, the chairman of urology and chief of robotic surgery at Lenox Hill Hospital in New York City.
The same cholesterol plaques that can build up in the arteries surrounding the heart can also affect arteries that go through penile tissue. Once doctors rule psychological causes, "they need to do a cardiac workup to make sure that this guy is not on the verge of getting a heart attack," Samadi told Live Science.
Causes
Since sexual arousal is a complex process involving hormones, emotions, nerves, muscles, blood vessels and the brain, a malfunction in any of these can lead to ED. Stress, exhaustion and psychological issues can also contribute, and anxiety over maintaining an erection can actually make it harder to attain. In short, any condition that inhibits blood flow to the penis can lead to ED.
Aging is a large part of ED, but according to the AAFP and the Mayo Clinic, ED can also be caused by:
- Heart disease or clogged blood vessels
- High blood pressure
- Diabetes
- Obesity
- Metabolic syndrome, a grouping of conditions that include high blood pressure, cholesterol and insulin levels and excess fat around the waist
- Multiple sclerosis
- Parkinson's disease
- Low testosterone
- Peyronie's disease, which is scar tissue inside the penis
- Certain prescription drugs, such as antidepressants and high blood pressure medication
- Smoking
- Alcoholism or drug addiction
- Prostate treatments
- Brain or spinal cord injuries
- Stroke
- Radiation therapy to the testicles
- Certain types of surgery on the prostate or bladder
The vast majority of ED cases are caused by disease, according to the National Institutes of Health (NIH), while drug side effects account for 25 percent.
Low libido, which is a low interest in having sex, should not be confused with ED, Samadi added.
People often have drops in testosterone levels as they age, often called male menopause or "manopause," Samadi said.
Diagnosis & tests
Doctors can rule out various systemic causes of ED with a physical exam. Breast enlargement in men, for instance, can indicate hormonal issues, while decreased pulses in the wrists or ankles can suggest blood flow problems, according to the NIH.
Beyond that, several tests can lead to an ED diagnosis. According to the Mayo Clinic, these include:
- Blood tests to check cholesterol, testosterone and glucose levels
- Urinalysis to look for signs of diabetes
- Ultrasound to check blood flow to the penis
- Overnight erection test to monitor erections during sleep. Physical causes of ED can be ruled out if the patient has an involuntary erection while sleeping (a normal occurrence), breaking a special tape wrapped around his penis.
Medication & treatment
A variety of drugs and treatments are available for ED, from simple pills to complex surgeries. The cause and severity of ED will determine which treatment is recommended, according to the AAFP. Some treatments can have significant side effects.
Psychotherapy is an option to treat anxiety-related ED, according to the NIH. The patient's partner can help in the process of developing intimacy and stimulation.
Oral medications successfully treat ED in many men, Samadi said. These include sildenafil (commonly known by the brand name Viagra), tadalafil (Cialis), vardenafil (Levitra) and avanafil (Stendra). Each works by enhancing naturally occurring nitric oxide, which relaxes muscles in the penis and increases blood flow.
However, these medications should not be taken by men who take blood thinners, high blood pressure medicines, nitrate drugs for angina, or alpha-blockers for an enlarged prostate. According to the NIH, the combination of ED pills with these other prescription medications can cause a sudden, dangerous drop in blood pressure.
Side effects include nasal congestion, headaches and a flushed face. If one medication doesn't work, another may do the trick. "We don't know why, but the chemistry of it may work differently on different people," Samadi said.
It's best to take oral medications on an empty stomach 60 to 90 minutes before having sex. If a person has a large meal, such as a steak dinner, the fatty food may absorb some of the medication and reduce its efficiency, except for Cialis, which stays in the body for a long time, Samadi said.
Other ED medications include:
- Alprostadil injections, which produce an erection in five to 20 minutes that lasts for about an hour. Patients use a fine needle to inject alprostadil (commonly known by the brand names Caverject Impulse and Edex) into the base or side of the penis. Side effects can include bleeding or fibrous tissue formation at the injection site as well as prolonged erection, according to the Mayo Clinic.
- Alprostadil penis suppository, which is inserted with a special applicator about 2 inches into the urethra. Side effects can include pain, minor bleeding, dizziness or fibrous tissue formation inside the penis.
- Testosterone injections to raise low hormone levels.
If medications don't work, more aggressive treatments may be recommended, including:
- Penis pumps, which involve placing a hollow tube over the penis and creating a vacuum that pulls blood into the penis with a hand- or battery-operated pump. According to the Mayo Clinic, a tension ring is placed around the base of the penis to maintain the erection until intercourse is finished.
- Penile implants, which surgically places rods into the two sides of the penis that are inflatable when desired.
- Surgery, which can repair arteries carrying blood to the penis or veins that allow blood to leave the penis.
Prevention
A variety of lifestyle choices can affect the ability to achieve and maintain an erection, so preventing ED is possible in some cases. Men are encouraged to manage chronic health problems with their doctors and to exercise regularly. They also should avoid smoking and excess alcohol and get help for anxiety or depression, according to the Mayo Clinic.
"There are a lot of benefits to healthy sexual function," Samadi said, "Whether it boosts the immune system or whether it is good for releasing stress. So certainly, you don't need to give up on it just because you're getting older."
Additional resources
- A man could have erectile dysfunction for any number of reasons. See a list of possible risk factors at the James Buchanan Brady Urological Institute at Johns Hopkins Medicine.
- Check out these healthy living tips from the Cleveland Clinic that may help improve sexual function.
- Just a quarter of men in a large U.S. study got prescriptions for their ED, reports Men's Health.
Additional reporting by Laura Geggel. Follow her on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+.
