Erectile Dysfunction

Erectile Dysfunction (ED) refers to the condition where the penis cannot become sufficiently erect to have sexual intercourse. Some may not achieve an erection, some may ejaculate prematurely, and some may experience pain during ejaculation.

The main cause is insufficient blood flow to the penis. The incidence increases with age, occurring in about 5% of men under 40 years old, and about 37.5% in men aged 40-70 years. This condition can be treated if identified and treated promptly. Those experiencing this problem should not worry,

as it is mostly temporary. If it is permanent, it may indicate psychological or physical issues. As men age, sexual function may change, such as requiring more time to achieve an erection, and the erection may not be as firm as in youth. Additionally, more stimulation may be needed, and the orgasm may differ from before, with less semen. This condition does not necessarily mean a decrease in sexual desire or ejaculation problems.

Structure of the Penis

The male penis consists of three tubes similar to spongy tissue called the corpus cavernosum—two tubes running parallel to the urethra on top—and one corpus spongiosum tube running underneath. When flaccid, the length is about 8.8 cm. When stimulated, blood flows into the spongy tubes, allowing them to expand up to 7 times, making the penis larger and erect with a length of 12.9 cm. As long as sexual arousal continues, the penis remains erect, but ejaculation causes blood to leave the penis, resulting in flaccidity.

Steps of Penile Erection

• It begins with sexual desire, which originates in the brain and can be stimulated by images, smells, sounds, touch, and thoughts.
• The sexual desire signal is transmitted to the spinal cord and then stimulates the penis, causing blood to flow into it.
• The blood vessels in the penis must dilate for blood to fully enter the penis.
  Therefore, any factors affecting these three mechanisms can cause erectile dysfunction.

Mechanism of Penile Erection

The erection of the penis requires the following important components:
• The arteries supplying the penis must not be narrowed because erection requires blood to pool. If the arteries are hardened, blood cannot fully supply the penis. Conditions causing arterial hardening include smoking, diabetes, high cholesterol, and hypertension.
• The peripheral nervous system, which receives sensations from physical touch.
• The spinal cord system, which connects sensory input from the peripheral nerves to the central nervous system and transmits commands to the penis.
• The central nervous system, which includes stimuli such as sight, hearing, smell, imagination, and past experiences. The mind plays an important role.

Symptoms of Erectile Dysfunction

• Inability to maintain an erection throughout sexual intercourse.
• Penis does not become fully erect.
• Complete inability to achieve an erection.
• If these symptoms persist for more than 2 months or recur, consult a doctor.

Causes of Erectile Dysfunction

Erectile dysfunction often has multiple causes. The more causes present, the higher the chance of occurrence. Factors include:

• Age: The incidence increases with age, with ED found in 20.4%, 46.3%, and 73.4% of men aged 40-49, 50-59, and 60-70 years, respectively.
• Socioeconomic status: Those with higher income, education, and better occupations have fewer ED problems than those with lower income.
• Chronic diseases: Chronic illnesses affecting arteries, veins, and penile muscles can cause ED, such as diabetes, kidney disease, chronic alcoholism, atherosclerosis. ED in this group occurs in about 70%. Important diseases include:
• Cardiovascular disease, which reduces blood flow to the penis.
• Hypertension.
• Diabetes, usually occurring about 10 years after diagnosis, mainly due to hardened blood vessels and autonomic neuropathy.

Erectile Dysfunction from Enlarged Prostate Disease

• Surgery and trauma affecting nerves controlling penile erection, such as pelvic surgery, prostate surgery, injuries to the penis, spinal cord, bladder, or pelvis, may damage nerves causing impotence. Transurethral surgery can also cause this.
• Medications: Various drugs may reduce sexual desire or cause impotence.
• Lifestyle behaviors include:
• Smoking: Smokers have a higher incidence of ED (45%) compared to non-smokers (35%).
• Alcohol consumption: Drinkers have an ED rate of 54%, compared to 28% in non-drinkers.
• Exercise: Those who exercise have a lower incidence than those who do not.
• Psychogenic ED accounts for about 10-20% of ED cases, often caused by stress, anxiety about work or family, fear of sexual failure, or criticism from partners leading to loss of confidence.

Causes of Erectile Dysfunction by Erection Mechanism

ED causes can be divided into 3 stages according to the erection mechanism:

• Failure to initiate erection, often due to psychological, brain, nervous system issues, or lack of male hormones.
• Failure of arterial blood to flow and pool in the penis, where the heart pumps blood but the penis does not expand or become sufficiently erect, usually due to poor blood circulation to the penis.
• Failure to trap arterial blood in the penis long enough to maintain a full erection and successful intercourse, often seen in older men with fibrosis replacing arteries.

Causes of Erectile Dysfunction by System

• Arterial abnormalities are the most common cause, including:
• Diabetes
• Hypertension
• High cholesterol
• Smoking
• Radiation therapy
• Long-distance cycling or motorcycling
• Neurological abnormalities, divided by levels as follows:
• Brain level: brain tumors, epilepsy, paralysis, Parkinson’s, Alzheimer’s disease
• Spinal cord level: most commonly due to trauma
• Peripheral nerves: commonly caused by diabetes, also seen in abdominal or prostate surgery patients
• Venous abnormalities: often found in elderly and diabetic patients due to venous sclerosis
• Hormonal abnormalities: men with low testosterone levels often have ED with decreased sexual desire but not necessarily erection problems.
• Psychological abnormalities, divided into two types: those with pre-existing mental illness such as depression or stress, and those with sexual problems like premature ejaculation or incomplete erection causing chronic anxiety.

Severity of Erectile Dysfunction

• Mild: able to have successful intercourse almost every time.
• Moderate: successful intercourse about half the time.
• Severe: unable to have successful intercourse.

Diagnosis

• Medical history including illnesses, current medications, frequency of sexual desire, erections, and ejaculation. Prepare this information for your doctor.
• Physical examination: palpate the penis to check for erection. Lack of erection may indicate nerve problems. Check for hair loss on the penis, which may be due to endocrine causes.
• Laboratory diagnosis: blood tests to check liver function, blood sugar, kidney function, lipids, and general blood tests. For those with low sexual desire, testosterone levels may be checked. Also, observe nocturnal erections; if erections occur at night or early morning, the cause is likely psychological.

Treatment

• Initial treatment involves eliminating or reducing risk factors by changing lifestyle habits such as eating high-fiber, low-fat foods, reducing salt, avoiding alcohol and smoking.
• Psychotherapy: psychological treatment to reduce anxiety if impotence is caused by mental factors.
• Drug therapy: includes oral medications, injections, or suppositories.
• The first-line oral medication should be taken 30 minutes to 1 hour before intercourse, preferably on an empty stomach. The drug acts for 4-5 hours, allowing some to have intercourse in the morning even if taken before bedtime. This medication works only if the user has sexual desire and increases blood flow to the penis. The usual dose is 50 mg per day, not to exceed once daily. For patients with liver or kidney failure or over 65 years old, start with 25 mg per day and increase if no complications occur. Contraindications include heart disease patients taking nitrates, as it may cause low blood pressure, fainting, and danger. Taking this drug with other antihypertensives is generally safe. Available drugs in Thailand include Levistra.
• Alpha-blocker drugs such as yohimbine [Procomil] were originally used to stimulate sexual desire but are now known to act on the brain and dilate peripheral blood vessels including the penis, enabling erection. Dosage is 18-30 mg daily for 1-3 months, but watch for complications like hypertension, palpitations, and frequent urination.
• Sublingual tablets act within 10-25 minutes with low side effects, mainly nausea and vomiting.
• Testosterone hormone therapy is suitable for those with low blood testosterone levels.
• Penile injections cause blood vessels to dilate, acting within 5-20 minutes and lasting about 1 hour. Side effects may include priapism (prolonged erection), pain at injection site, and bleeding.
• Urethral suppositories act within 8-10 minutes and last 30-60 minutes. A constriction ring is needed to maintain erection. Side effects include urethral irritation and possible bleeding.
• Vacuum devices: a vacuum pump is placed over the penis to remove air, drawing blood into the penis to achieve erection, followed by a constriction ring to maintain it.

Surgery

There are three surgical methods:

• Implanting prosthetic tubes into the penis connected to a pump to induce erection.
• Surgery to repair arterial blockage due to trauma, suitable for younger men.
• Surgery to repair venous leakage is less commonly performed.
  Treatment choice depends on age and existing diseases. Inform your doctor of any conditions before treatment, as some may be dangerous during sexual activity, such as:
• Recent heart attack or stroke within the past 2-3 months.
• Certain arrhythmias.
• Uncontrolled angina due to coronary artery disease.
• Uncontrolled hypertension.
• Uncontrolled heart failure.
• Severe valvular heart disease.

Consult a Doctor

• Exercise the penis to keep it strong.
• Avoid alcohol and drugs.
• Quit smoking.
• Exercise regularly.
• Reduce stress and anxiety.
• Get adequate rest.
• Have annual health check-ups.

Although erectile dysfunction may occur occasionally in men, it can be reduced by the following methods:

Prevention