Impotence or erectile dysfunction is a common problem among men when a man is not able to get erection which is firm enough for sexual intercourse. Erectile dysfunction usually is caused by underlying medical problems. Causes and risk factors of erectile dysfunction can be classified into two categories: physical and psychological causes and risk factors. There are many tests and diagnostic methods to diagnose erectile dysfunction, such as physical exam, Urinalysis, blood tests, nocturnal penile tumescence, injection test, duplex doppler penile ultrasound, mental health exam, etc. Furthermore, men with erectile dysfunction can be treated by medications, surgical procedures, and erection devices. Taking some steps can prevent erectile dysfunction. These steps include managing chronic diseases, quitting smoking, healthy diet, and regular physical activities.

Impotence or erectile dysfunction is a common problem among men when a man is not able to get erection which is firm enough for sexual intercourse. Erectile dysfunction is present when a man can get erection from time to time, the erection does not last long enough for sex, or he cannot get erection at all.

Causes and risk factors for erectile dysfunction can be divided into two categories:

Physical causes and risk factors

There are some disease and disorders that cause damage to arteries, nerves, fibrous tissues, and muscles of the penis, such as:

• Aging.
• Obesity.
• Diabetes.
• High cholesterol.
• Cardiovascular disease like atherosclerosis, hypertension, and hyperlipidemia.
• Chronic kidney disease.
• Multiple sclerosis, a disease that attacks the nerves.
• Injuries resulting from prostate cancer treatments such as radiation and prostate surgery.
• Spinal cord, penis, bladder, prostate, or pelvis injuries.
• Bladder cancer surgery.
• Peyronie’s disease, a disorder which causes penis tissue scars.
• Some medications like those prescribed for Hypertension, High cholesterol, psychiatric disorders, and prostate cancer,
• Smoking.
• Acromegaly, a condition causing enlargement of the bones.
• Hypogonadism in which the testes are not able to make enough testosterone.
• Sleep apnea.
• Thyroid disease. 
• Cushing's syndrome which affects the production of cortisol hormone.

Psychological causes and risk factors

Psychological problems, as the following, can cause or contribute to having erectile dysfunction:  

• Depression.
• Anxiety.
• Stress.
• Relationship problems.
• Low self-esteem.
• Fear of sexual failure.

The process of getting an erection is a complex one that includes integration of psychologic state, anatomic structures, vascular system, endocrine system, and neurologic system. According to several studies, sexual arousal is activated in cortical centers which stimulate the paraventricular nuclei and medial preoptic of the hypothalamus. This in turn activates parasympathetic nerves in the sacral area.

The occurring neurovascular events result in the inhibition of adrenergic tone and the release of the nonadrenergic, noncholinergic neurotransmitter nitric oxide. It is believed that nitric oxide is released from endothelial cells and nerves called noncholinergic neurotransmitter nitric oxide nerves abbreviated as NANC. It subsequently stimulates the guanylate cyclase enzyme system in penile smooth muscle which causes enhancement of arterial inflow, smooth muscle relaxation, and veno-occlusion, producing adequate firmness of the penis.

Erectile dysfunction symptoms include:

• Persistent inability to get erection.
• Persistent troubles in terms of keeping an erection long enough for sex.
• Persistent reduced or low sexual desire.

Usually, erectile dysfunction is diagnosed after some answers of the doctor’s questions and physical exam. But, if the doctor suspect an underlying cause or the patient has a chronic disease, the doctor may ask for further tests:

Physical exam

Health care providers check if the penis is sensitive or not, unusual characteristics that may refer to the problem, breast enlargement or body hair loss to point a possibility of hormonal problems, pulse to see if the patient have problems in blood circulation, and blood pressure.

Blood tests

 They are helpful for detecting underlying problems that cause erectile dysfunction, such as cardiovascular disease, diabetes, hormonal problems, and chronic kidney disease.   

Urinalysis

They are urine tests with purpose of detecting diabetes, chronic kidney disease or any other underlying problems of erectile dysfunction. 

Nocturnal penile tumescence

 It is called also overnight erection test. This test requires wearing a special device around the penis to detect if it gets erections because men usually have from 3 to 5 erections while sleeping. If a patient has erections, it means that he is physically capable of having erection which most probably refers to psychological issue causing erectile dysfunction.

Color duplex Doppler

Color duplex Doppler, called also Duplex Doppler penile ultrasound, is a minimally-invasive method for measuring blood flow and check for signs of a venous leak, atherosclerosis, or tissue scarring. During the exam, some kind of medication can be injected in the penis to cause an erection.

Injection test

Injection test, known as intracavernous injection, is a test in which a medication is injected into the penis to cause an erection so the doctor can evaluate the state of the penis. Sometimes, the medication could be inserted into the urethra instead of injecting it into the base of the penis.

 Mental health exam

The doctor may interview the patient and ask him some questions in order to help diagnose any emotional or psychological problems that cause the erectile dysfunction, such as depression and anxiety.

Dynamic infusion cavernosometry and cavernosography

Dynamic infusion cavernosometry is procedure in which fluid is pumped into the penis to measure the vascular pressure in the corpus cavernosum during an erection. In cavernosography, an opaque material to x-rays is injected into the penis which will give accurate visualizations of any leakage.

Magnetic resonance angiography    

Magnetic resonance angiography, similar to magnetic resonance imaging, uses magnetic fields and radio waves in order to give accurate and detailed images of blood vessels. A contrast agent may be injected into the patient's bloodstream to have enhanced information about any blood supply and vascular problems.

Erectile dysfunction has various treatment options depending of the severity of it and underlying causes:

Medications

• Oral medications

Erectile dysfunction oral medications are considered to be successful option and they include:

• Tadalafil 

Tadalafil is taken 1 to 2 hours before having sex with or without food. This medication can be effective for up to 36 hours.

• Avanafil 

Avanafil effectivity can last for 6 hours. Depending on its dose, avanafil is taken 15 to 30 minutes before having sex.

• Sildenafil

Sildenafil is well known to be very effective medication if taken on an empty stomach around 60 minutes before the sexual intercourse. The duration of its effectivity can last 6 hours.

• Vardenafil

Vardenafil can be taken 60 minutes before the sexual intercourse with or without food and to ensure its effectivity which could last for up to 7 hours.

Non-oral medications

• Injections

Many men achieve stronger erections by injecting medications into their penises because trigger automatic erections. Best examples of such medications are alprostadil, phentolamine, and papaverine. The erection achieved by injections lasts usually about 20 to 40 minutes. When the effectivity lasts more than 60 minutes, the dose should be adjusted.

• Alprostadil urethral suppository

For men who do not like injections, they can insert a suppository or pellet or of alprostadil into their urethras using a special applicator in order to deliver the suppository around 1 inch or 2.54 centimeters into the urethra. The goal of such therapies is to start having an erection within 10 minutes and it may last up to 60 minutes.  

• Testosterone replacement

Doctors may recommend testosterone replacement therapy to those who have erectile dysfunction and low hormone testosterone levels which is delivered in many forms, such as patch, gel, injection, subcutaneous pellet, etc.

Vacuum erection devices

A vacuum erection devices or a penis pump is put on the penis in order to suck the air creating some sort of vacuum which pulls the blood into the penis causing an erection that lasts long enough to have sex.

Surgical treatments  

In case there are no results after using the abovementioned options, the patient is more likely to be advised to do one of the following surgical procedures:

• Penile prostheses

Penile prosthesis or penile implant is a surgical procedure in which a medical device is implanted within the corpora cavernosa of the penis. Penile prosthesis has two main types:

• Bendable implant: The simplest form of it can be described as two silicon rods that are easy to bend allowing the patient to get the erection needed for sexual intercourses. 
• Inflatable Implant: the simplest form of it is a pump that pushes fluid into cylinders placed in the scrotum to induce an erection then it draws it back when the erection is not needed.

• Penile revascularization

Penile revascularization, or microvascular arterial bypass surgery for erectile dysfunction, is a surgery to increase the amount of blood flowing to the penis. Penile revascularization benefits men who have vascular injuries reducing blood flow to the penis. On the other hand, the surgery would not get results to those who have erectile dysfunction caused by hypertension, atherosclerosis, or any other vascular diseases. 

• Venous Ligation Surgery

Venous ligation is a procedure to block off leaky veins of the penis to allow more blood to flow to the penis and having a proper erection for having sex. However, this procedure is not a popular choice because the success rates on the long-term are not good.

Psychological treatment

Psychological or mental health problems such as depression, stress, and anxiety, causing the erectile dysfunction should be addressed. Besides, if the erectile dysfunction is causing relationship issues and stress, the patient will be recommended to visit a counselor or psychologist. 

Making healthier life choices, and taking some preventive steps can help prevent several causes erectile dysfunction:

Managing chronic diseases

Men who have chronic disease , such as diabetes, or high blood pressure should follow their doctors’ recommendations and instructions regarding managing their illnesses and preventing erectile dysfunction. Also, prescribed medications should be taken as directed.

Reviewing medications

Medications should be reviewed with the patient’s doctor and to make sure they do not cause erectile dysfunction. If the patient feels that his medication is causing erectile dysfunction, he should ask the doctor before changing or stopping taking the medication.   

Regular exercises

Regular exercises and physical activities in general enhance blood flow throughout the penis. It is highly recommended that men should counsel their doctors before starting any new activity. Exercises or physical activities should be practiced at least 30 minutes most of the week days.

Quitting Smoking

Smoking is increase the risk of having cardiovascular diseases, and erectile dysfunction as well. So, quitting smoking or tobacco use plays a substantial role in preventing erectile dysfunction.

Healthy diet

A Healthy diet that contains whole-grain foods, fruits, vegetables, lean meats and low-fat dairy products helps prevent erectile dysfunction since it is good to avoid obesity, and cardiovascular disease. In addition, too much alcohol, using illegal drugs, and high fat and sodium foods should be avoided.

Complications of erectile dysfunction include:

• Unfulfilled or unsatisfactory sex life.
• Depression, anxiety.
• Intimacy loss between the couple, and relationship tension as a result.
• The inability to get the partner pregnant.
• Feeling ashamed and low self-esteem.

Although it is a tough challenge that can change men’s life and lower or decrease their self-esteem, the outlook for men with impotence or erectile dysfunction is very good in general. Aging is often associated with erectile dysfunction, but growing older isn’t necessarily one of the main causes of it because aging is nothing more than a risk factor.

It is well-known that erectile dysfunction can have very negative effects on sex life, but still it is a treatable condition and there are several treatment options and interventions that can help a person regain his sexual function, including medications, and lifestyle changes.

Since erectile dysfunction can refer to an underlying medical problem, the patient should visit a doctor especially if the problem becomes persistent even if he thinks that stress is the cause.