Erectile Dysfunction (ED): Symptoms, Causes, and Treatment
Written By Kobi Nathan, Pharm.D., M.Ed., CDP, BCGP, AGSF
Sleep Disorders
October 21, 2022

What is erectile dysfunction?

Erectile dysfunction is the consistent inability to have or maintain an erection throughout sexual activity. While not a serious condition, it can have an impact on your quality of life.

Erectile dysfunction is most prevalent in older men.

One study determined that mild to moderate ED has an incidence of 52% in men ages 40 to 70 years old.

There are roughly 19 to 66 new cases for every 1,000 men each year.

ED is associated with increased age, emotional status, pre-existing conditions, and overall health.

Other studies indicate that erectile dysfunction has a higher prevalence in the United States and southeastern and eastern Asian nations compared with other world regions.

We do not know why this occurs; however, it is likely due to environmental and genetic differences (1).

What causes erectile dysfunction?

Historically, experts believed that psychological issues caused ED.

However, erectile dysfunction is more often associated with physical blood supply to the penis and is usually caused by underlying conditions (2).

Knowing your risk factors for ED and what may cause ED is critical to understanding how to prevent and treat ED. I have listed the potential causes of erectile dysfunction into four categories below:


  • Prostate issues
  • Diabetes
  • Hyogonadism (when the testes don’t make enough hormones)
  • High blood pressure
  • High cholesterol
  • Chronic sleep disorders (e.g., insomnia, sleep apnea, etc.)
  • Priapism (prolonged erection – medical emergency!)
  • Peyronie’s disease (curvature or distortion of the penis)
  • Certain chronic diseases, such as renal failure and dialysis
  • Injury from prostate cancer treatments, such as radiation and surgery
  • Injury to the penis, prostate, bladder, spinal cord, or pelvis


  • Blood pressure medications
  • Antiandrogens (medications that treat prostate cancer)
  • Antidepressants
  • Sedatives (medications that make you calm or sleepy)
  • Appetite suppressants (medications that make you less hungry)
  • Ulcer medications

Mental problems

  • Depression
  • Anxiety
  • Fear about sexual performance or failure
  • Stress (about sex or in general)
  • Poor self-esteem


  • Poor sexual technique
  • Being overweight
  • Inadequate interpersonal relationships
  • Smoking
  • Illegal drugs
  • Alcohol
  • Low physical activity
  • Diet (2,3)

What are the signs and symptoms of erectile dysfunction?

Signs and symptoms of ED can include:

  • The inability to have an erection when you want to have sexual intercourse
  • The ability to have an erection but it not lasting long enough for sex
  • The ability to have an erection sometimes but not every time you want to have sex (3)


Medical form with Erectile dysfunction ED diagnosis.

How is erectile dysfunction diagnosed?

To diagnose ED, your doctor will review:

  • Your medical and sexual history. This helps to understand what diseases or conditions might be causing your erectile dysfunction. You may fill out or answer a questionnaire describing your ability to get and maintain an erection and your satisfaction with sex.
  • A physical examination. Your provider will look for potential neurological, physical, or circulatory problems that may be the root cause of the ED.
  • A psychosocial examination. Providers may ask you questions to help determine what mental factors may be causing your ED.
  • Laboratory tests. These tests may include a urinalysis, lipid profile, blood count, and getting enzyme levels. They may also measure how much testosterone is in your blood. Testosterone levels can be an indicator of certain other conditions, such as decreased libido (2).

Impact on quality of life

Quality of life is perhaps one of the most important measures of disease burden and treatment success.

Erectile dysfunction can affect you both physically and mentally. One study evaluated men with erectile dysfunction.

Results indicated that approximately 75% of men who thought their ED was a problem were not satisfied sexually.

Additionally, erectile dysfunction can have psychological effects. Commonly men with ED will feel demasculinized. You may experience low confidence, low self-esteem, anxiety, or depression.

These negative thoughts and feelings can create a cycle. Oftentimes, after facing the challenges of ED before, men can develop anticipatory anxiety.

With this, men may feel overwhelmed or stressed about their sexual dysfunction and performance, which only further exacerbates ED symptoms.

Erectile dysfunction can also have impacts on your partner and your sexual relationships. In the same study mentioned above, 82% of females with partners that had erectile dysfunction reported low levels of sexual satisfaction (4).

Who treats erectile dysfunction?

Most men with erectile dysfunction can seek care for their ED with their primary care physician.

Your PCP can start you on basic, first-line medications for your symptoms. If you are unsuccessful with these agents, your PCP may refer you to a urologist.

A urologist can help assist you in trying out other treatment options such as using a vacuum device, injections, or surgery.

You may also consider seeing a counselor who specializes in sexual dysfunction.

When seeking a professional opinion, it is important to remain honest about your experiences and symptoms.

Some questions your provider asks may seem embarrassing or private, but this information is important to better understanding your condition (1).

Cardiovascular risk with EDCVD

Men that have erectile dysfunction are at increased risk for cardiovascular disease (CVD) and other medical conditions.

If you are diagnosed with ED, your doctor should evaluate your risk for future cardiovascular problems. Your physician will be able to manage certain pre-existing conditions or refer you to a specialist to lower your risk of CVD.

Because ED and CVD commonly occur together, sexual activity may put you at risk for cardiac problems.

For example, sexual activity has been known to cause certain cardiac events. A cardiologist will be able to assess your risk factors or underlying heart disease and see if you can engage in sexual activity.

Your cardiac risk is lower if you regularly exercise. Therefore, if you are at risk for CVD, your doctor may recommend lifestyle modifications. There are several lifestyle changes that you can implement to reduce this risk while also improving ED symptoms (5).

Medical Treatments for ED

When treating erectile dysfunction, the goal is to achieve and maintain an erection.

The first step to treatment involves correction of the underlying cause, if any.

For example, if your doctor thinks one of the medications you are on may be causing your ED, they may switch you to an alternative therapy or adjust your dose.

If there is no underlying cause that can be corrected, your doctor will start treatment in a stepwise manner. The general treatment algorithm is as follows:

  1. Identification of underlying causes of ED that are curable
  2. Lifestyle modifications and patient education/counseling. Initial treatment will usually involve lifestyle modifications. These will require you to adhere to a proper diet and exercise regimen in hopes that behavior changes will improve your symptoms. If lifestyle changes alone do not work, your health care provider may prescribe you medication.
  3. Treatment with medication and other therapies. There are multiple medications and methods available for ED. First-line therapies include medications known as PDE5 inhibitors and vacuum erection devices (VEDs). Second-line therapies include intraurethral suppository (IUS) of alprostadil and intracavernosal injections (ICI) (1). These will be discussed in further detail throughout the rest of the article.

Lifestyle modifications

Through your doctor’s examination, they will assess you for certain modifiable risk factors that may be causing your ED. A big risk factor includes certain lifestyle behaviors, specifically low exercise, poor diet, and being overweight.

Modifying these factors can have a big impact on erectile dysfunction symptoms, especially in younger individuals.

Changing your lifestyle and modifying your risk factors should be the first step you take treating your ED.

Additionally, you should continue to follow these guidelines even if you choose to start medication or other therapies.

Lifestyle modifications include:

Weight loss

In fact, a person with a 42-inch waist is 50% more likely to have erectile dysfunction than a person with a 32-inch waist.

Research indicates for obese men, weight loss through adherence to a Mediterranean diet and exercise can improve ED symptoms.

Additionally, obesity can lead to diabetes and vascular disease which can both cause ED.

Finally, too much fat can cause hormone imbalances which may contribute to ED symptoms. You should aim to achieve a BMI of less than 30.

Regular physical activity

Experts recommend that adults undergo moderate-intensity aerobic exercise for at least 30 minutes daily.

Other studies suggest that in men with congestive heart failure, moderate exercise improved sexual function.

Implementing a proper diet

The Massachusetts Male Aging Study demonstrated that eating a diet full of natural foods lessened the incidence of ED.

As aforementioned, you may benefit from eating a Mediterranean diet full of fruits, vegetables, fish, and whole grains that includes limited refined grains and red and processed meats.


Experts also recommend smoking cessation if you are a smoker. Research shows that there is a correlation between the number of cigarette packs smoked or years of smoking and the severity of ED. Your risk of having ED almost doubles if you are a smoker.

Limiting alcohol intake

Chronic alcohol use or abuse can cause erectile dysfunction. Too much alcohol can negatively affect the liver, causing low testosterone levels and increased estrogen levels. Both alterations can contribute to ED.

Reducing psychological stressorsSTRONG BRAIN

Erectile dysfunction can arise from mental health issues, everyday stress, relationship problems, and anxiety in the bedroom.

If you experience any of these, you may benefit from counseling by a psychologist or a medical professional that specializes in sexual dysfunction.

This can help you to restore your confidence, work through limiting beliefs, and manage day-to-day anxieties.

If diagnosed with anxiety or depression, your mood and ED symptoms may benefit from proper medication.

Communication with your partner

As aforementioned, erectile dysfunction can affect both you and your partner.

When navigating ED, it is important to maintain open communication with your partner and both maintain a proactive attitude surrounding pleasure.

This will help to relieve any anxieties surrounding sexual performance. Couples may even benefit from seeing a licensed counselor together who specializes in sex (1,6).

Prescription medications for improving erectile function

When treating erectile dysfunction, it is important to have reasonable expectations about the effects of treatment.

For example, ED medications will not be effective in those that have normal function. The rest of this article will discuss the various treatment options that are available for ED.

Phosphodiesterase type 5 (PDE5) inhibitors

PDE5 inhibitors represent a major medication class in the treatment of ED. There are four main PDE5 inhibitors: sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis), and avanafil (Stendra).

There are slight differences between each product, which may lead your doctor to select one over the other.

The selection of the right agent will depend on your patient-specific factors.

It is also important to note that treatment failure with PDE5 inhibitors occurs in 30 to 40% of men.

You should continue therapy with PDE5 inhibitors for five to eight doses before considering treatment failure.

How do PDE5 inhibitors work?

PDE5 is an enzyme that plays a role in a man’s ability to have an erection. In the body, PDE5 causes the breakdown of a substance known as cyclic guanosine monophosphate (cGMP).

cGMP is important to achieving and maintaining an erection because it causes smooth muscle relaxation and increased blood flow.

When PDE5 breaks down too much cGMP, ED can occur.

PDE5 inhibitors work by blocking the PDE5 enzyme, therefore preventing the breakdown of cGMP.

Increased levels of cGMP increase blood flow and relax the smooth muscle.

This phenomenon causes you to have and maintain an erection (7).

Are PDE5 inhibitors safe?

The most frequent side effects of PDE5 inhibitors include:

  • Headache
  • Indigestion
  • Flushing
  • Dizziness
  • Stuffy nose
  • Vision problems

Rare side effects of PDE5 inhibitors include:

  • Priapism (prolonged erection)
  • Nonarteritic ischemic optic neuropathy (NAION), a condition causing vision loss (8)

Cost of PDE5 inhibitors

When selecting a PDE5 inhibitor, it is important to consider the cost.

Traditionally, only expensive brand-name PDE5 inhibitors were available on the market.

More recently, however, pharmaceutical companies have made generics for certain PDE5 inhibitors.

This makes them less expensive and gives you more freedom when selecting a PDE5 inhibitor agent. You will also have to consider your insurance coverage when selecting an ED medication (7).

Drug interactions/Contraindications with PDE5 inhibitors

Nitrates (e.g., nitroglycerin): Nitrates should never be taken at the same time as a PDE5 inhibitor.

  • Wait at least 24 hours after taking sildenafil or vardenafil before taking nitroglycerin
  • Wait at least 48 hours after taking tadalafil before taking nitroglycerin
  • Wait at least 12 hours after taking avanafil before taking nitroglycerin

Alpha-blockers: When taken together, PDE5 inhibitors and alpha-blockers can cause seriously low blood pressure. Your doctor may have to adjust your doses if you must take both types of medications.

CYP3A4 inhibitors: Certain medications are inhibitors of the drug-metabolizing liver enzyme CYP3A4. Examples include certain antifungals, antibiotics, and antiviral medications. Your doctor may need to adjust your doses if you take one of these medications (7).

Overview of PDE-5 Inhibitors

MedicationDoseImportant Points
Sildenafil (Viagra)50 mg 30-60 minutes prior to sexual activity
Maximum dose: 100 mg

Onset: 30 minutes
Duration: 4-5 hours

Take on an empty stomach because fatty foods reduce absorption
Do not exceed 25 mg if you have reduced kidney or liver function or if you are over 65 years of age
Tadalafil (Cialis)10 mg up to 2 hours prior to sexual activity
Maximum dose: 20 mg

Onset: 2 hours
Duration: 36 hours

Do not exceed more than 1 tablet every 24 hours
Do not exceed more than 5 mg every 72 hours if you have reduced kidney function
Do not exceed more than 10 mg if you have reduced liver function
Vardenafil (Levitra, Staxyn)10 mg 30-60 minutes prior to sexual activity
Maximum dose: 20 mg

Onset: 1 hour
Duration: 4-5 hours
Fatty foods reduce absorption
Do not exceed 5 mg if you have reduced liver function
Avanafil (Stendra)50-100 mg 15-30 minutes prior to sexual activity
Maximum dose: 200 mg

Onset: 15 minutes

Do not use if you have reduced renal function or are on hemodialysis (7)


Prostaglandin E1

Prostaglandin E1, or alprostadil, is another medication that can treat ED. It is not taken by mouth.

Instead, you administer it via either the intracavernosal or intraurethral route.

With an intracavernosal (IC) injection, you give a shot into the base of the penis.

With intraurethral (IU) alprostadil, you place a suppository (pellet) into the urethra. These routes of administration will be described in more detail below.

How does prostaglandin E1 work?

Prostaglandins are important substances made by our bodies that control certain bodily functions.

Alprostadil is a naturally produced prostaglandin called prostaglandin E1 (PGE1). It works in ED by binding to the PGE receptor. This activates an enzyme known as adenylate cyclase.

Activation of adenylate cyclase increases levels of cAMP in the body. cAMP is a substance that causes smooth muscle relaxation and promotes blood flow. By increasing cAMP, alprostadil causes an erection.

Overview of Prostaglandin E1 Agents

MedicationDoseSide EffectsImportant Points
IC alprostadil
(Caverject, Edex)
Individualized dose injected 5-10 minutes before intercourse,

Onset: 5-15 minutes
Maximum dose: Do not exceed more than 1 injection per day and 3 injections per week

Penis painMassage the penis after injection to distribute drug to other side
IU alprostadil
125 to 250 mcg administered 5-10 minutes prior to sexual activity

Onset: 5-10 minutes
Maximum dose: Do not exceed more than 2 doses per day

Penis pain, burning of the urethra, dizziness, headache, testicular pain, minor bleedingMake sure to fully empty the bladder before administration (8)

How do PDE5 inhibitors and PGE1 (alprostadil) compare?

The main differences between PDE5 inhibitors and alprostadil include the route of administration and the details listed below.

PDE5 inhibitors vs Prostaglandin E1

PDE5 inhibitors

PGE1 (alprostadil)
Require stimulation to be effective
Should not be used in patients that have significant cardiovascular problems
Have a lower risk of priapism (painful erection)
Automatic erection
Has a maximum number of doses per month
Requires sterile technique
Has a higher risk of priapism (painful erection)

Vacuum devices for ED

Vacuum therapy (VT) is another method used to treat ED. However, it is not a medication.

It is a physical device used to create an erection-like state. The vacuum erection device is a plastic tube that you place around the penis.

After lubricating the penis, you pump air out of the tube, creating a vacuum-like effect. This method increases blood flow to the penis, causing an erection.

After achieving an erection, you can place a ring around the penis and remove the tube.

The ring keeps blood from leaving the penis and allows you to maintain the erection.

After using the vacuum pump and placing the ring, you will have an erection and can begin intercourse. The ring should not be left on for more than 30 minutes.

While a great option, vacuum devices are not perfect. Some men and their sexual partner might find that they perceive VT-derived erections differently than a natural erection.

You may also experience certain side effects such as pain, numbness, and bruising. Some men report also having trouble with ejaculation due to the ring.


  • Erectile dysfunction is a very common condition that occurs in men.
  • ED can be burdensome to both you and your partner, but proper management can relieve symptoms.
  • Men with ED should first implement lifestyle changes such as weight loss, proper diet, adequate exercise, and smoking cessation.
  • If ED symptoms persist, you can try one of the many agents available to treat erectile dysfunction in addition to lifestyle modifications.
  • The mainstay of ED treatment is PDE5 inhibitors.
  • There are four types of PDE5 inhibitors available: sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis), and avanafil (Stendra).
  • All are relatively safe and effective. However, your doctor should consider your cardiovascular risk and drug interactions prior to treatment.
  • You may also try intracavernosal or intraurethral alprostadil. While they are not oral medications, they create an automatic erection. Vacuum therapy is a physical device that is also available and can create an erection.
  • Selecting a medication or therapy for your ED is a personal decision.
  • You should always consider the efficacy and safety of a treatment before starting it. Discuss with your doctor which ED therapy may be the best for you.


  8. Lexicomp

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