Erectile Dysfunction


What is erectile dysfunction (ED)?
Erectile dysfunction (ED) occurs when a consistent inability to get or maintain an erection prevents you from having satisfying sex. A man with ED either loses his erection before or during intercourse, gets only a partial erection, or gets no erection at all. ED is sometimes called impotence, but the preferred term is ED.

How common is ED?
Because ED is somewhat open to definition, it is tough to accurately estimate the number of sufferers. There are no universally agreed-upon criteria for how consistent an erection problem has to be and for how long it has to continue in order for it to qualify as ED. Plus, it can be hard to determine the number accurately because many men don't like to talk about it.

But some studies suggest that 20% of men in their 50s, and about 18 million Americans between the ages of 40 and 70, have ED to some degree. Worldwide, it's estimated that ED affects about 100 million men. And ED need not be chronic to make its presence felt. Other studies suggest that almost all men experience occasional difficulty getting or maintaining an erection. In many cases, it's just temporary and needs only short-term treatment.

Who typically gets ED?
Poor physical and emotional health can contribute to ED. ED also is associated with medical conditions such as diabetes, hypertension, high cholesterol, and prostate disease. The more factors affect a man, the higher his risk of ED. However, even relatively healthy men can experience ED.

Age can also be a concern. ED is more likely to happen as a man gets older, particularly after he's 60. The occurrence of some degree of ED is 39% in men 40 years old, and 67% in those aged 70 years. ED can happen at any age, even after years of satisfying sex.

Nevertheless, age itself doesn't cause ED. Rather, it's the more frequent occurrence of certain health issues in older men, such as vascular diseases and diabetes, that accounts for the increase in ED with age.


Erectile dysfunction is characterized as the inability to achieve an erection when trying to have sex, an erection that does not last long enough for sex, or the inability to get an erection at all. Occasional ED is often nothing serious, but when it becomes frequent or bothersome to the patient, that's when they should speak to their health care provider.


What are the common causes of ED?
Erections reflect the brain's complex interaction with the penis/pelvic area. Nerves and chemicals cause the penis muscles to relax and allow blood flow to the penis to increase, resulting in an erection. Anything that interferes with this intricate process can cause ED.

Common causes of ED include:

  • Physiological disorders: diabetes, high blood pressure, cholesterol elevation and some cardiovascular conditions can block blood vessels and impair blood flow to the penis. Certain hormone problems and medications can also cause ED.
  • Neurologic disorders: a stroke or multiple sclerosis, for example, can interfere with the brain's ability to communicate with the rest of the body. Such miscommunication during sexual functioning could cause ED. If different areas of the brain, nerves, or spinal cord are damaged, proper messages will not be relayed to the penis.
  • Psychological: ED can stem from relationship problems, performance anxiety, stress (job, family, financial), a history of sexual abuse, guilt or fear associated with sexual behavior, and depression or other mental illnesses.

What health problems are associated with ED?
Impaired blood flow, either to or from the penis, is the most common cause of ED. Various diseases, such as diabetes, high blood pressure and hardening of the arteries (atherosclerosis), can affect the flow of blood. In fact, atherosclerosis causes roughly 40% of ED in men older than 50 years.

Diseases affecting the nervous system can interfere with the body's ability to process sexual stimulation signals, also causing ED. Nerve damage from strokes or spinal injuries, and other neurological disorders, like multiple sclerosis and Parkinson's, change the brain's ability to respond to sexual stimulation, potentially preventing an erection.

Diabetes is a disease that affects both the vascular and nervous systems. Approximately 50% of diabetic patients, irrespective of type, have ED.

ED can also result from a fractured or crushed pelvis that leaves the man's nerves or arteries damaged, inhibiting the flow of blood to the penis.

Likewise, some types of pelvic surgeries and radiation therapies, such as those used in the treatment of prostate, bladder or rectal cancer, can cause ED .

Endocrine disorders such as low levels of testosterone, or thyroid or pituitary gland problems, can also cause a hormone imbalance and erectile problems.

Diseases such as Peyronie's disease, an inflammatory condition that produces scarring within the penis, causing it to curve or bend, can also contribute to ED.

Sometimes, medications taken to treat illnesses are behind ED. Blood pressure therapies like beta-blockers, some heart medications, some peptic ulcer medications, sleeping pills, and antidepressants fall into this classification.

Lifestyle choices may also contribute. Alcohol or other drug abuse, a poor diet and smoking may be associated with vascular disease, hardening of the arteries and high blood pressure--all of which are, in turn, associated with ED.

Other chronic-disease states associated with ED include: chronic renal failure; hepatic failure; Alzheimer's disease; sleep apnea; and chronic obstructive pulmonary disease.

Very often, a combination of several factors causes ED. As the number of risk factors or conditions often leading to ED increase, the man's risk of ED rises correspondingly.


The diagnosis of ED is easy. Determining why ED is occurring, on the other hand, can be more difficult. Identifying the cause of ED usually begins with a structured interview, followed by a physical examination, and possibly laboratory testing.

Determining whether a person suffers from ED rather than other sexual problems of ejaculation, orgasm, or sexual desire is an essential first step. Once ED is established, a doctor will determine the nature of ED. Finding the cause begins by asking many of the questions listed below in order to obtain a medical, sexual and psychological history. These questions can be helpful in determining the severity of ED and revealing possible medical conditions or diseases that may be contributing to, or merely complicating, a man's ED. Sometimes a doctor may also ask their patient to complete a questionnaire regarding their sexual function which can confirm the presence of ED.

After this structured interview, a physical examination is performed in order to help identify physical problems that may be causing ED.

Questions Commonly Asked During the Medical History
What questions do doctors ask when discussing ED with patients?

The kinds of questions a doctor might ask about ED are:

A. Questions relating to the specific erectile complaint:

  1. How long have these symptoms been present? Did they begin gradually or suddenly?

Your doctor needs to know if this is a new problem or one that has been ongoing for some time.

2. Do you wake up with an erection? How about in the evening?

Men naturally have erections while they sleep and when they wake up in the morning. This is one way your doctor might determine the severity or cause of the problem.

3. If you do have erections, how firm are they? Is penetration difficult?
The doctor needs to get a sense of how severe ED is since dissatisfaction can vary.

4. How consistent is the problem: Is penetration difficult 50%, 75% or 100% of time?

5. Do your erections change at different times such as with different partners, oral stimulation, or masturbation?

Does ED vary from one circumstance to another, or is it consistent throughout all sexual experiences?

6. Are there any difficulties with sexual desire (libido), arousal, ejaculation, or orgasm (climax)? If so, did these difficulties occur before or after the onset of the ED, or are they separate issues? It is possible that your ED is due to, or occurring in conjunction with, a different sexual dysfunction?

7. What effect is this problem having on your sexual satisfaction, your sexual confidence, or your relationship (if you are in one)?

B. Questions relating to medical factors that could be contributing to ED:

  1. What medical conditions do you have?

ED is strongly linked to a number of other common diseases in men such as: diabetes, heart disease, high blood pressure, high cholesterol, vascular disease, neurologic conditions, chronic liver or kidney disease.

2. What medications are you currently taking?

There are a number of medications that may cause, or contribute to ED.

3. If and how much do you smoke, drink, or use other drugs?

Certain lifestyle habits increase a man's likelihood of having ED. Alcohol or drug abuse can contribute to heart disease, hardening of the arteries and hypertension, all of which can lead to ED.

4. Is there a new curve or bend to the penis? If curvature is present, is it painful? What is the location and severity of the curvature?

Peyronie's disease, which is an inflammatory condition that produces scarring within the penis, causing it to curve or bend, can also contribute to ED.

5. Any previous history of surgery or radiation therapy, particularly in the pelvic region?

For example, treatments for prostate disease may also cause ED.

6. Any history of pelvic, genital, or spinal cord trauma?

Injury to these areas can sometimes interfere with the body's ability to develop and maintain an erection.

C. Questions relating to psychosocial factors that could be contributing to ED:

  1. How is your relationship with your partner? Has anything changed recently?

ED can sometimes be a result of marital (or relationship) problems.

2. What is your sex life like? Has anything changed recently?

This sometimes leads to questions about the quality of your sexual relationships and sexual intimacy, such as frequency, sexual expectations from you and your partner, or any performance anxiety that may exist.

3. In general, are you under a lot of stress? Or has anything particularly upsetting happened to you?

Excessive stress from any aspect of life - work, relationship, financial, etc. may lead to ED

4. Have you been feeling down and depressed a lot? Do you have any psychological illnesses or have you considered seeing a psychologist?

Depression or other mental illnesses can contribute to ED.

D. Questions relating to prior evaluation or treatment:

  1. What testing have you have done to date?
  2. Have you used any treatments for ED? What kind or response have you obtained? Have you been using them properly?
  3. Did you experience any side effects from the medications?

Laboratory Testing and Imaging

Some simple laboratory tests may be performed. These tests include:

  • Blood tests
  • Testosterone: Deficiency in this sex hormone can be linked to sexual dysfunction
  • Blood sugar levels - screening for diabetes.
  • Lipid profiles - determines cholesterol and triglyceride levels, possibly indicating arteriosclerosis (which can reduce blood flow to the penis).
  • Liver enzymes and serum creatinine - disease of the liver or kidney can create hormonal imbalances.
  • Thyroid function - production of sex hormones and regulation of metabolism is done by thyroid hormones.
  • Urinalysis - also analyzes sugar and hormone levels that may indicate diabetes, as well as kidney dysfunction and testosterone deficiency. In some men, further tests may be required in order to help identify the cause of ED. These include erectile function tests, such as:
  • Vascular testing: the most commonly performed tests
  • Injection testing - Agents that cause increased blood flow are injected into the erectile chamber of the penis to cause an erection. The response to the medication may aid the physician in defining the cause of the problem.
  • Duplex ultrasound - Also called Doppler color-flow mapping or Doppler ultrasound - It is a form of ultrasound that allows physicians to see the structure and blood flow through blood vessels.
  • Dynamic infusion cavernosometry/cavernosography (DICC) - A sophisticated penile blood flow test conducted in some men with ED and penile abnormalities, usually done at major medical centers or by ED experts.
  • Neurological testing: these tests are rarely done these days.
  • Penile biothesiometry - Electromagnetic vibration is used to evaluate penile sensitivity and nerve function.
  • Somatosensory evoked potentials - Electrical, tactile or another type of stimulation of the nerves to determine nerve damage and function.
  • Pudendal electromyography - The pudendal nerve is the main nerve supplying the pelvis, bladder, and urethra. Damage to this nerve can cause ED. Electromyography is a test that doctors use to detect nerve function and measure the electrical activity generated by muscles. Therefore, this test can determine if damage to the pudendal nerve is the cause of ED.
  • Nocturnal penile tumescence - Men normally have erections when asleep at night, if not, this may be indicative of a problem with nerve function, hormones, or blood supply to the penis.

Questions to ask your provider
Many men find it awkward to talk about their erectile dysfunction for the first time. It can therefore be helpful to write down a few questions to ask your health care provider. We've provided a few common questions about ED to give you a head start.

  • How can I know whether my erectile dysfunction has a psychological cause or is the result of an underlying medical condition?
  • Is erectile dysfunction just an inevitable part of getting older, or should it be treated at any age?
  • Do you think my erectile dysfunction is related to cardiovascular disease, kidney disease, diabetes, or another serious medical condition?
  • Do I need to see a different type of health care provider, such as a urologist, endocrinologist, psychiatrist, or sex therapist? Why or why not?
  • How much of a role do things like diet, alcohol consumption, smoking, exercise, and amount of sleep play in either causing or treating erectile dysfunction?
  • If you find that my ED is caused by an underlying medical condition, will my ED be any more or less treatable?
  • What types of ED treatment are available?
  • What type of treatment do you recommend? What are the pros and cons of the possible treatments?
  • If this treatment is not successful, what would be the next step?
  • I've heard a lot about oral medications such as sildenafil, tadalafil, or vardenafil. Would one of these be appropriate for me?
  • I heard an ad on TV for an ED medication that I should ask my doctor whether I'm healthy enough for sexual activity. Can you explain what they mean by that?



What factors determine which treatment a doctor recommends for ED patients?
Erectile dysfunction has many causes, both physical and psychological. Initial management for ED depends on the possible cause of the disorder in each individual patient. Treatment options for ED have significantly improved over the past few years and new research and medications continue to increase treatment choices. Treatments offered depend on the expertise of the physician you see. For example, a urologist may offer you a greater scope of treatments than a family physician.

Deciding which treatment is best depends on a number of factors, including:

  • Whether the cause of a patient's ED is physical, psychological or both
  • The presence of other medical conditions
  • The possibility of interaction with other medications
  • Which option is most likely to be effective for a particular patient
  • The preferences of the man and his partner

Physical issues that may cause varying degrees of sexual dysfunction include: injury or surgery; underlying medical conditions, such as diabetes and/or cardiovascular disease; lifestyle issues, such as smoking and the use of alcohol or other substances; and side effects of medications used to treat other conditions. Psychological issues that can lead to ED include performance anxiety, stress or secondary sexual dysfunctions (premature, delayed and/or retrograde ejaculation).

While the first step of good medical practice is to alter controllable risk factors (such as smoking, obesity, and alcohol abuse; stress, fatigue, depression; the adjustment of prescription medications etc.), most patients with ED will need an additional form of treatment. Therapies currently available include: sexual counseling and education, oral medications, injection therapy, vacuum devices and surgical treatments.

To determine an optimal treatment plan, physicians, patients and partners must have open and honest discussions of all available options. The process of care model outlines the general approach to treatment. First-line therapy includes (1) an attempt to correct controllable risk factors (2) addressing overt psychological issues (For example, if ED commences during the first relationship after a divorce, after being widowed or where obvious confidence issues are not being helped by medical therapies, such as a sex psychologist) (3) oral therapy (pills), which at this time is limited to the use of PDE5 inhibitors, such as sildenafil citrate (Viagra®), vardenafil hydrochloride (Levitra®) and tadalafil (Cialis®).

Second-line treatment includes the use of vacuum devices, intra-urethral (urine channel) suppositories and penile injection (intracavernosal) therapy and is typically reserved for men who have failed pills or have significant side effects and cannot tolerate these medications. Third-line therapy is for patients who have explored first- and second-line therapy and includes vascular surgery for very specific populations of men and penile implant (prosthesis) surgery.

Is treatment for ED covered by insurance? Are the medicines covered?
Treatment and medicine coverage by healthcare insurance varies from one insurance provider to the next, as well as from one plan to the next. It is best to contact the individual provider in order to determine whether the prescribed treatment(s) for ED is covered by insurance.

What non-surgical treatments are available for ED?
The most common non-surgical treatments for ED include:

Condition overview written by Tobias S. Kohler, MD, MPH and Landon W. Trost, MD