Sexual Wellness

Erectile Dysfunction: Symptoms, Causes, and Treatments

Fact Checked

One of the most common causes of ED comes down to the partial obstruction and narrowing of blood vessels caused by dyslipidemia (i.e., high fats in the blood, high cholesterol), smoking, diabetes, and coronary artery disease.

Last Updated: 01/08/2022

Written by

Warren Dutton

Medically Reviewed by

Dr. Paul Thompson

Erectile Dysfunction: Symptoms, Causes, and Treatments

Approximately 50% of men over the age of 40 years experience some form of erectile dysfunction (ED). Experts consider this disorder as a contributor to poor quality of life.(1)

To achieve an erection, the body integrates complex physiological processes, involving the central nervous system, peripheral nerves, hormones, and blood vessels. If a defect develops in any of these systems, erection, ejaculation, and the ability to perform sexual intercourse may get compromised.

One of the most common causes of ED comes down to the partial obstruction and narrowing of blood vessels caused by dyslipidemia (i.e., high fats in the blood, high cholesterol), smoking, diabetes, and coronary artery disease.(2)

In fact, this effect is so pronounced that many experts recommend screening for cardiovascular risk factors in patients with ED. As it appears, ED is perhaps the earliest presentation of vascular disease.

Furthermore, scientists found a genetic component to ED, explained by the necessity to produce proteins during sexual intercourse. Therefore, there may be a genetic predisposition that increases the risk of ED in healthy individuals.(3)

The epidemiology of erectile dysfunction

Complete erectile dysfunction is defined as the inability to obtain or sustain an erection during sexual intercourse. Moreover, patients with complete ED report no nocturnal erections.

According to reports, 52% of men have some degree of erectile difficulty, whereas 10% have complete ED. As for mild and moderate cases of ED, they occurred in 17% and 25% of responders, respectively.(4)

The numbers reported by the Massachusetts Male Aging Study (MMAS) estimate that between 18 and 30 million Americans have a form of erectile dysfunction.(5)

In one paper released by the National Health and Social Life Survey (NHSLS), 10.4% of men aged 18–59 stated that they were unable to achieve or maintain an erection in the past year.(6)

As you can see, various sources report different numbers depending on the studied samples. However, the prevalence of ED is without a doubt significant enough to be a public health problem.

When it comes to international statistics, the risk factors and epidemiology seem to be similar to the United States.

Age-related demographics

All the studies that inspected the epidemiology of erectile dysfunction found a strong correlation between age and this disorder.

Other risk factors associated with aging and induce ED are:

  • Major depressive disorder (MDD)

  • Sleep apnea - a condition where brief, repeated episodes of breathing arrest occur

  • Dyslipidemia (e.g., high LDL, low HDL)

Researchers believe that the prevalence of ED will only increase with time due to the high number of risk factors associated with aging (e.g., blood hypertension, diabetes, vascular disease, lower urinary tract infections, prostate surgery, benign prostatic hyperplasia).

Finally, the real incidence and prevalence of ED could be severely underestimated since doctors do not routinely ask their patients about this condition.

What causes erectile dysfunction?

Generally speaking, the causes of erectile dysfunction are diverse; however, the final result is typically the same.

Every patient with ED has some form of abnormal blood flow to the penis, which prevents erection and ejaculation. Consequently, an erection might not occur or be temporary.

Researchers identified numerous conditions and factors that could cause erectile dysfunction, including:(7)

  • Increased age

  • Cardiovascular disease

  • Diabetes

  • High blood pressure

  • Parkinson’s disease

  • Multiple sclerosis (MS)

  • Peyronie’s disease

  • High cholesterol

  • Obesity

  • Low testosterone levels

  • Kidney disease

  • Stress

  • Anxiety

  • Depression

  • Relationship problems

  • Drugs used for blood pressure and depression

  • Sleep disorders

  • Drug abuse

  • Alcohol abuse

  • Using tobacco products

  • Damage to the pelvic area through injury or surgery

Several elements could be affected by this pathogenesis:(8)

  • Smooth muscle damage

  • The absence of vasodilators (e.g., nitric oxide)

  • Partial obliteration of the penile blood vessels (i.e., atherosclerosis)

Unfortunately, these mechanisms are different, which means different therapeutic approaches may be necessary.

If the patient is old or the damage is too severe, there is a low chance for a full recovery.

The signs and symptoms of erectile dysfunction

In order to assess a patient with erectile dysfunction, your doctor will conduct a comprehensive review of their medical and surgical history, physical examination findings, and test results.

Due to the ‘taboo’ nature of ED, many clinicians face challenges when they are trying to address this topic with their patients. This is especially true when the patient is not comfortable with the topic. However, when taking the medical history is done correctly, it could be a great opportunity to communicate with the patient and establish a rapport.

Here is a breakdown of some common steps to dissect the clinical presentation of ED:

Sexual history

Inquiring about sexual history can feel quite uncomfortable, but it is a very important step in the process. Usually, your doctor will ask you the following question:

How is your sexual life?

If you are dealing with troubles in bed, you need to inform your doctor regardless of how unpleasant the situation is. After all, it is always better to intervene early on in the disease process.

Once your doctor starts considering the possibility of an ED diagnosis, he/she will ask you follow-up questions to determine the characteristics of your disorder.

You can expect the following questions:

  • Do you face difficulty obtaining an erection?

  • Is the erection sustainable enough for penetration?

  • Can you maintain an erection until your partner achieves an orgasm?

  • Is the process of ejaculation impaired?

  • Do you and your partner reach sexual satisfaction?

When your doctor collects your sexual history, it will allow them to form an objective opinion about your condition.

Some patients may also present with premature (early) ejaculation, which generally occurs in men over the age of 40.

Unfortunately, premature ejaculation can lead to dire consequences among the couple. Typically, your doctor will prescribe selective serotonin reuptake inhibitor (SSRI) medications and sex therapy to effectively treat this condition. 

Medication and nonprescription drug history

It is vital to get a list of the drugs you are taking, in order to assess the impact of these substances on your sexual function. Your doctor may ask you for a list of the vitamins, minerals, and supplements you took during the past year.

Here is a list of medications that may contribute to erectile dysfunction:(9)

  • Lipid-lowering drugs (e.g., statins, fibrates)

  • 5-Alpha reductase inhibitors (e.g., finasteride, dutasteride)

  • Antiulcer drugs (e.g., proton pump inhibitors, cimetidine)

  • Antipsychotic drugs (risperidone)

  • Antihypertensive drugs

  • Antidepressants

  • Testosterone and anabolic steroids

Besides prescription drugs, the use of tobacco, alcohol, and illicit drugs may also be responsible for ED. By far, smoking remains the most important factor since it greatly impacts vascular function.

Psychological history

All the factors that cause stress and anxiety should be explored by your doctor. Whether you are dealing with stress at work or home, your psychological status needs to get assessed.

Some of the points that your doctor may focus on include:

  • Symptoms of depression

  • Loss of libido

  • Insomnia

  • Lethargy

  • Moodiness

  • Performance anxiety

  • Stress from work or other sources

  • Problems and tension in the sexual relationship

In reality, pure psychogenic impotence is relatively uncommon. Patients will report good nocturnal and morning erections, with negative findings on objective tests. However, we should not forget that many patients with organic ED have a psychogenic component.

Therefore, a history of variable erections that may be present during one day only to completely disappear the day after is a strong hint of psychogenic ED.

Note that almost 100% of patients with severe forms of major depressive disorder have ED.

Diagnosis of erectile dysfunction

To diagnose erectile dysfunction, your physician will follow a multistep process that begins with taking your medical, surgical, sexual, and psychological history.

The next step revolves around performing a thorough physical exam to check your vitals and the anatomy of your genitals (i.e., the penis, testes). In some cases, your doctor may also perform a digital rectal exam to palpate the prostate, which is commonplace for abnormal growths.

This long process allows your doctor to eliminate several differential diagnoses that may explain your sexual dysfunction.

When ED is psychogenic in nature, your doctor will ask you about whether you develop erections while asleep and the classic nocturnal penile tumescence (i.e., the morning wood).

Nocturnal penile tumescence

To perform this test, a healthcare professional will place several bands around the penis. These bands will be connected to a device that monitors changes in length.

In most clinics, you will need to wear this assembly for 2–3 successive nights. If an erection occurs, the device will record its force and duration. Depending on the results, your doctor will be able to differentiate between organic and psychogenic causes of erectile dysfunction.

Simply put, if an erection occurs during testing, it indicates that the cause of your ED is psychological. Conversely, absent erections for 2–3 successive nights imply an organic problem.

While this method of testing used to be the gold standard in identifying the etiology of ED, it is rarely used in current practice today.

You see, most clinics have advanced devices that provide a ton of information about the state of penile function. For instance, new machines (e.g., RigiScan) can measure the size of the penis when flaccid and erect, as well as the rigidity of the erection (i.e., resistance to physical compression).


The use of duplex ultrasonography allows for the evaluation of vascular function within the penis. Your doctor will measure blood flow in the cavernosal arteries before and after the injection of a vasodilator.

The treatment options for erectile dysfunction

The advances made in the treatment of erectile dysfunction have drastically improved the sexual lives of patients.

These treatments can be divided into a few categories:

1.  Oral treatments

The most commonly used drugs to treat erectile dysfunction are:

  • Viagra (Sildenafil)

  • Cialis (Tadalafil)

  • Levitra (Vardenafil)

  • Stendra (Avanafil)

The primary difference between these drugs revolves around their duration of action, side effects, and popularity.

For instance, Viagra is the most popular drug because it has been around since 1998. Conversely, Cialis is a relatively newer drug (2003) that has numerous advantages, including:

  • Faster onset of action – 30-60 minutes

  • Longer duration of action – up to 36 hours

  • Fewer side effects

2.   Injectable treatments

  • Alprostadil (Caverject, Edex)

Alprostadil is the only injectable drug approved by the FDA for monotherapy. After drug administration, the muscles of the penis relax, giving you a rigid erection.

  • Papaverine/Phentolamine (Bimix)

Bimix consists of two drugs to give you a long-lasting erection. This drug is particularly beneficial for individuals who are sensitive to low levels of injectable medication for erectile dysfunction.

  • Papaverine/Phentolamine/Aprostadil (Trimix)

Trimix has three active ingredients that use different mechanisms to induce an erection. According to research, men who use Trimix injections along with oral medication for ED report a higher level of satisfaction.

  • Papaverine/Phentolamine/Aprostadil/Atropine sulfate (Quad-mix)

Adding atropine sulfate to Trimix gives us Quad-mix. Atropine promotes the relaxation of the smooth muscles found in the penis to give you a rigid erection.

According to the American Urologic Association, intracavernous injection is the most effective non-invasive treatment for erectile dysfunction.(10)

The direct injection of the medication into the penis produces a long-lasting response, which is not the case for oral drugs.

You can give yourself the injection 5 minutes before sexual activity. The effect of the injection starts to wear off after 1 hour. You will find more instructions down below.

The most common indication for injections is the failure to respond to regular oral therapy. The drugs that often get injected include alprostadil, papaverine, and phentolamine.

While these medications can be used separately, combining two or more compounds produces a synergistic effect.

Depending on the number of drugs combined, the following products are available:

  • Bi-Mix

  • Tri-Mix

  • Quad-Mix

The products are not available on the market and need to be compounded by specialty pharmacies. You will also need a prescription from your doctor to get these drugs.

The steps you need to take when self-injecting Bi-Mix, Tri-Mix, or Quad-Mix:

The first phase – getting started

  • Wash your hands and make sure your penis is clean.

  • Prepare the syringe, an alcohol swab, and the injectable solution (Bi-Mix, Tri-Mix, or Quad-Mix).

The second phase – the syringe

  • Clean the rubber top of the vial with alcohol.

  • Remove the cap of the needle and fill the syringe with air (you can do this by pulling back the plunger).

  • Insert the needle into the rubber of the vial and pull back the syringe until you reach the desired dosage.

  • Use one finger to tap the side of the syringe – this will allow the air bubbles to float.

Phase three – the site of the injection

  • The site of the injection is between the base and mid-portion of the penis at 9-11 and 1-3 o’clock.

  • You need to avoid the midline due to the location of the urethra. You also need to avoid injecting near-visible veins or arteries.


    Place the head of the penis near the side of your leg and select the injection site.

  • Clean the site of injection with alcohol.

Phase four – the injection

  • Insert the needle at a 90-degree angle into the site of injection.

  • Gradually push the Bi-Mix, Tri-Mix, or Quad-Mix solution.

  • Apply pressure at the site of injection (1–2 minutes). If you start bleeding, this duration may be extended.

  • Get rid of the needle and syringe in the appropriate container.

3. Platelet-rich plasma (PRP)

Platelet-rich plasma (PRP) refers to a body fluid that contains platelets, giving it the ability to heal damaged tissues and restore lost functions.

When you have erectile dysfunction, your doctor may take a blood sample from a specific location (e.g., bone marrow, fat cells). The next step involves the isolation of the platelets to produce platelet-rich plasma (PRP).(11)

Once the solution is ready, your doctor will apply local anesthesia and inject the PRP into your penis. In most cases, the solution will also contain stem cells, which have the ability to become any type of cell/tissue. Therefore, if the blood vessels inside your penis get damaged, stem cells will be able to repair them.

The goal of this therapy is to restore erectile function, which is possible via the repair of damaged tissues and the regeneration of new endothelial cells.

When you complete the first session of treatment, you may start seeing results after as soon as 48 hours.

It is important to note that the effectiveness of this therapy generally lasts for one year. When this duration ends, you will most likely need another injection.

4.  Surgical treatment

  • Surgical revascularization

As mentioned above, some patients develop ED after a traumatic event to the pelvic arteries. In these cases, revascularization procedures, such as rotating the epigastric artery into the corpora (i.e., plural of corpus cavernosa), can be beneficial. 

Learn more about the anatomy of the penis by clicking on this link (insert link of the Peyronie’s disease article).

The AUA recommends this treatment for healthy patients who recently acquired ED due to trauma or arterial obstruction. The patients should not have any history of generalized vascular disease.(12)

  • Surgical elimination of venous outflow

When the blood enters the penile arteries and flows through the arteries, the high pressure compresses the veins, preventing the blood from returning to the general circulation. As a result, an erection occurs.

In some cases, patients have small leaks through the veins, which gives merit to a surgical procedure designed to eliminate venous outflow.

Unfortunately, and despite the initial enthusiasm for this procedure, the lack of long-term efficacy contributed to abandoning this therapy.(13)

Your doctor may also suggest penile implants if you have Peyronie’s disease with ED. Furthermore, other surgeries may be appropriate, especially when the spinal cord is involved (it affects the nerves that cause erections and ejaculation).

The outcome of patients with erectile dysfunction

In one study that included 1709 men aged 40–70 years, researchers found that ED is associated with an increased risk of all-cause mortality. In other words, patients with ED are more likely to die from various causes. Of course, this does not suggest that ED is responsible for the death of the patient. It only shows a correlation between ED and mortality rates. The vast majority of deaths were the result of cardiovascular events.(14)

In another study released by the Prostate Cancer Prevention Trial database, scientists found that ED patients were more likely to develop a cardiovascular event relative to men without ED.(15)

Moreover, an analysis confirmed the connection between ED and increased risk of cardiovascular events.(16)

The analysis reported that men with ED had a: 

  • 44% increased risk of cardiovascular events

  • 25% increased risk of all-cause mortality

  • 62% increased risk of myocardial infarction (i.e., heart attack)

The good news is that the effective treatment of ED with lifestyle modifications and pharmacological drugs may improve the prognosis of patients and lower their risk of heart disease.

Frequently Asked Questions (FAQs) about erectile dysfunction

Which lifestyle modifications are necessary for erectile dysfunction (ED)?

As a general rule of thumb, regular exercise and a healthy diet are necessary to improve erectile function. Additionally, there is some evidence that weight loss lowers inflammation and boosts testosterone levels, which could be beneficial for patients with ED.

Speak with your doctor about the best measures to improve your lifestyle and reduce the psychological toll of ED.

Diabetic patients should pay close attention to their blood sugar to prevent vascular damage. Also, taking antihypertensive drugs to control high blood pressure may help with ED.

What are the DSM-5 criteria for the diagnosis of erectile dysfunction (ED)?

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), gives erectile dysfunction the following definition:(17)

“A sexual dysfunction that presents with the inability to be sexually active or experience sexual pleasure.”

Because sexual functioning involves a variety of components (e.g., biological, sociocultural, psychological), it is often challenging to ascertain a clinical cause of ED.

The DSM-V states that before making the diagnosis of ED, other mental disorders that trigger male sexual dysfunction must be considered.

  • Partner factors (e.g., partner sexual problems)

  • Relationship factors (e.g., poor communication, different levels of sexual desire, domestic violence)

  • Individual vulnerability factors (e.g., history of sexual abuse, depression, stressful job)

  • Cultural or religious factors (e.g., conflicted attitudes regarding sexuality)

  • Medical factors (e.g., medical disorders, medications, illicit drugs)

With that out of the way, the specific criteria to diagnose ED are:

  • The patient must have 75–100% of their sexual activity impaired. Additionally, at least one of the following symptoms need to be present:

  • Marked difficulty to obtain an erection

  • Marked difficulty to maintain an erection 

  • A marked decrease in erectile rigidity

  • The symptoms must persist for at least 6 months

  • The symptoms need to cause psychological distress for the patient

  • The sexual dysfunction cannot be explained by other medical conditions, drug intake, or relationship stressors

The duration of the sexual dysfunction is specified as follows:

  • Lifelong (it presents during the first sexual experience)

  • Acquired (it occurs after a period of normal sexual function)

What are the differential diagnoses for Erectile Dysfunction?

Erectile dysfunction has several differential diagnoses that may confuse the clinician during the workup.

These include:

  • Abdominal Vascular Injuries

  • Depression

  • Hemochromatosis

  • Hypogonadism

  • Hypopituitarism (Panhypopituitarism)

  • Noncoronary Atherosclerosis

  • Peyronie Disease

  • Scleroderma

  • Sickle Cell Anemia

  • Type 2 Diabetes Mellitus

How is erectile dysfunction (ED) prevented?

The best way to prevent ED is by controlling its risk factors. For instance, diabetes, heart disease, and chronic blood hypertension all contribute to developing ED. Therefore, the optimal management of these disorders could significantly lower the incidence of sexual dysfunction.

Moreover, erections require a healthy vascular function, which means that the following activities all improve blood flow to the penis and lower the risk of ED:

  • Smoking cessation

  • Maintenance of ideal body weight

  • Regular exercise

  • Healthy diet

  • Avoiding a sedentary lifestyle

In one clinical trial, researchers inspected the effects of the Mediterranean diet on individuals with type II diabetes. The results showed that the men who followed this diet were significantly less likely to develop ED compared to the placebo group.(18)

Note that it is optimal to speak with your healthcare provider before attempting any new diet.

What is the role of Peyronie’s disease in the etiology of erectile dysfunction (ED)?

Peyronie disease precipitates the scarring and curvature of the penis, which could impact the flow of blood when the fibrosis is severe enough.

Over time, Peyronie’s disease could cause ED; however, this cause of ED requires a more robust intervention that includes pharmacological drugs and surgical procedures.

To learn more about Peyronie’s disease, check out this link (insert link of the previous article).

Takeaway message

Erectile dysfunction is a very prevalent disorder that affects the person’s sexual life and may precipitate mental issues. Thanks to the advances made in the field of medicine and surgery, the treatment of erectile dysfunction is more efficient than ever. Additionally, the number of cases that stem from psychological etiologies makes the treatment relatively easier.

Speak with your doctor to get tailored medical advice about the best therapeutic approaches for erectile dysfunction.