Defined as an inability to maintain an erection sufficient for sexual intercourse at least 25 percent of the time, erectile dysfunction can also signal an underlying health condition that may require treatment.
Causes and Risk Factors of Erectile Dysfunction
The causes of erectile dysfunction include:
Vascular Disease: Also known as arteriosclerosis, vascular disease is a condition in which the arteries harden and narrow, resulting in a reduction in blood flow throughout the body. The reduction in blood flow to the penis can lead to impotence. Age-related arteriosclerosis is responsible for more than half the cases of impotence in men over 60. Risk factors for arteriosclerosis include diabetes mellitus, high blood pressure, and high cholesterol.
Smoking: Generally considered the biggest risk factor for impotence, smoking is related to arteriosclerosis because smoking reduces blood flow.
Diabetes Mellitus: Damage to small blood vessels and nerves from chronic high levels of blood sugar, which is associated with diabetes mellitus, can impair the transmission of nerve impulses and/or blood flow necessary for erection. Approximately 60 percent of male sufferers of diabetes melitus experience impotence.
Drugs: Impotence is a side effect of drugs that affect the vascular and nervous system. More than 200 prescription drugs, such as drugs for high blood pressure, as well as many over-the-counter medications, fall into this category and can cause impotence.
Hormone Disorders: A deficiency in testosterone can cause impotence. An excess of prolactin, which reduces testosterone, can have the same effect.
Pelvic trauma: Erectile dysfunction can result from surgery of the rectum, colon or prostate; or as a side effect of radiation therapy in that area of the body.
Obesity: Overweight men are more likely to experience erectile dysfunction than thin men.
Metabolic Syndrome: Men with unhealthy cholesterol and triglyceride levels, high blood pressure, belly fat, and insulin resistance are at a higher risk for erectile dysfunction.
Neurologic Conditions: Any condition that results in an interruption of nerve impulses or damage to the nerves from the brain to the penis, including spinal and brain injuries, nerve disorders, multiple sclerosis or Parkinson's disease, may cause impotence.
Prolonged Bicycling: Pressure from a bicycle seat can compress nerves and influence blood flow to the penis, leading to temporary erectile dysfunction and penile numbness. Radiation therapy for prostate or bladder cancer may also damage these nerves.
Peyronie's Disease: An inflammatory condition, peyronie's disease causes scarring of erectile tissue. This can cause curvature of the penis and can interfere with sexual function. Inflammation may also be responsible for pain during erections.
Venous Leak: A venous leak is a leak in the veins of the penis. Because leakage allows blood to leave the penis during erection, an erection is unable to be maintained. Venous leak can occur from damage to the veins in the penis caused by injury or disease.
Psychological Conditions: Emotional states including depression, stress, guilt, worry, anxiety, and low self esteem can lead to a loss of libido and erectile dysfunction.. Psychological factors, however, are less relevant than physical causes.
Alcoholism and/or substance abuse
Chronic health conditions: Endocrine system disorders can cause erectile dysfunction.
Diagnosing Erectile Dysfunction
Your physician will perform a complete physical examination to check for neurological, vascular or hormonal diseases, or for Peyronie's disease. The physician will ask for a complete history of any family illness, especially of hypertension, as well as a history of smoking, drug use, and past and current medications. Laboratory tests will be performed to identify possible underlying causes of erectile dysfunction.
Blood Tests and Urinalysis
Blood tests may indicate or confirm conditions that may interfere with normal erectile function. These tests measure hormone levels, cholesterol, blood sugar, liver, kidney, and thyroid function.
Levels of sex hormones are also measured. An excess of prolactin (hyperprolactinemea) can lower testosterone levels, which can diminish libido. If they are persistently low, an endocrinologist (hormone specialist) should be consulted.
Complete blood count (CBC)
Both red and white blood cells are measured in order to evaluate the possible presence of anemia. A low level of red blood cells limits the body's ability to use oxygen and causes fatigue. The level of blood lipids (fats) can signal the presence of arteriosclerosis, which can reduce blood flow to the penis.
Liver and kidney function tests
Liver and kidney disease can create hormonal imbalances, which can cause erectile dysfunction. Blood tests for liver function are based on an analysis of enzyme and serum creatinine levels. These are indicators of kidney efficiency.
Thyroid function tests
Thyroid hormones regulate metabolism and the production of sex hormones. A deficiency may be a contributing factor of impotence.
Urine is analyzed for protein, sugar and hormone levels that may indicate diabetes mellitus, kidney dysfunction or testosterone deficiency.
Duplex ultrasound is used to evaluate blood flow, possible venous leak, signs of artherosclerosis and scarring or calcification of erectile tissue. Erection is induced by injecting prostaglandin, a hormone-like stimulator produced in the body. Ultrasound is then used to see vascular dilation and measure penile blood pressure. Measurements are compared to those taken when the penis is flaccid.
A digital rectal examination (DRE) can detect an enlarged prostate, which can interfere with blood flow to the penis, as well as the transmission of nerve impulses.
Penile Nerve Function
A diagnostic, such as a bulbocavernosus reflex test, determines whether there is sufficient nerve sensation in the penis. When the glans (head) of the penis is squeezed, if nerve function is normal, this will cause the anus to contract. Latency is measured between the squeeze and the contraction. If a patient has diabetes or nerve damage, specific nerve tests will be used.
Nocturnal Penile Tumescence (NPT)
Five to six erections during sleep, especially during rapid eye movement (REM), are considered normal. Their absence can indicate possible issues with nerve function or blood supply in the penis. During nocturnal erection, there are two ways of measuring fluctuations in penile rigidity: snap gauge and strain gauge.
Three plastic bands of varying strength are wrapped around the penis. Erectile function and circumference are measured according to which bands break.
Elastic bands are placed at the base and tip of the penis. As the bands stretch during erection, changes in circumference are measured.
Sensitivity and nerve function in the glans and shaft of the penis are measured with electromagnetic vibration. Decreased perception of vibration can be a sign of nerve damage in the pelvic area, which can lead to impotence.
There are several solutions that cause erection by dilating blood vessels in erectile tissue. These solutions can be injected into the penis to measure pressure. X-rays that use a special contrast agent may be taken at the same time of the penile blood vessels.
Possible nerve damage is assessed by the physician conducting a physical examination to test for normal touch sensation in the genital area.
Dynamic Infusion Cavernosometry and Cavernosography (DICC)
Dynamic Infusion Cavernosometry and Cavernosography (DICC) involves injecting a dye into penile blood vessels. The dye makes visible any abnormalities in blood pressure and blood flow into and out of the penis. This procedure is generally performed under local anesthesia by a urological specialist in erectile dysfunction.
Treating Erectile Dysfunction
Naturopathic (Natural) Treatment
Lifestyle and nutritional choices that may can contribute to difficulties achieving and maintaining an erection include:
- Long term alcohol use
- Long term tobacco use
- Long term use of recreational drugs
- Poor nutrition, including an excess of processed foods
By improving overall health, natural treatments, good nutrition, and supplements can help improve erectile function. Vascular disease in particular may respond to nutritional changes and herbal support, and thus help improve erectile dysfunction.
Whole, fresh, unrefined and unprocessed foods, fruits, pigmented berries, soy, seeds, olive oil, nuts, whole grains, vegetables, beans, and cold-water fish, including salmon, tuna, sardines, halibut, and mackerel are recommended to help treat erectile dysfunction.
Foods to avoid include dairy products, refined and fried foods, junk foods, caffeine, and sugar. Avoid any food that might cause sensitivity. It is also recommended to drink 50 percent of your body weight in ounces of water daily. A 200 pound man should drink 100 ounces of water a day.
Exercises that support the cardiovascular system can increase energy and assist in relaxation, which in turn can help treat erectile dysfunction. Aerobic exercise and weight training are also recommended.
Flexible or inflatable rods or tubes are surgically inserted into the penis, providing the necessary rigidity for intercourse. Concealment can be difficult, however, depending on clothing.
Inflatable Penile Prosthesis
Two soft silicone or plastic tubes are inserted in the penis, a small reservoir is implanted in the abdomen, and a small pump is implanted in the scrotum. To produce an erection, a man pumps sterile liquid from the reservoir into the tubes by squeezing the pump in the scrotum. Functioning as erectile tissue, the tubes expand to form an erection. Afterward, the fluid is returned to the reservoir via a valve.
Vascular Reconstructive Surgery
Vascular reconstructive surgery can improve blood flow to the penis. In revascularization, blocked veins or arteries are bypassed by using a vein transferred from the leg, which is then attached to create a new path to the penis. Young men with only local arterial blockage are best suited for this procedure.
A procedure to prevent venous leak. Problematic veins are bound (ligated) or removed, allowing an appropriate amount of blood to remain in the penis.
Drug Therapy: Self Injection
Self-injection requires the injection of a small dose of medication into the side of the penis. Because a small needle is used, the injection is relatively painless and creates an erection. Various drugs have been approved by the FDA for other medical uses, but only prostaglandin has been formally approved for impotence.
Urethral Suppositories (MUSE)
The eurethra is capable of absorbing some medications into the adjacent tissues. MUSE suppositories with prostaglandin EL (alprostadil) can be inserted to create an erection. Possible side effects include:
- Aching in the penis, testicles, legs and between the scrotum and the rectum
- A burning sensation in the urethra
- Redness of the penis
- Minor urethral bleeding
Medical Device Therapy (vacuum devices)
Vacuum devices (simple mechanical tools that allow a man to develop an erection suitable for sexual intercourse) bring increased blood to the penis and then trap it there. The penis is inserted into a hollow plastic tube and then pressed against the body to form a seal. A small hand pump creates a vacuum, which in turn, draws blood into the penis, causing it to enlarge and become rigid. After several minutes in the vacuum, a soft rubber O-ring is placed around the base of the penis to trap blood and maintain the erection. When the vacuum tube is removed, the rubber ring maintains the erection until removed. It can remain erect up to 30 minutes. These devices may be harmful for men with blood clotting problems or men who use blood thinners.
Psychological issues can cause impotence, therefore psychological therapy may be effective if used with medical or surgical treatment.
Oral medications used to treat erectile dysfunction include selective enzyme inhibitors (e.g., sildenafil [Viagra®], vardenafil HCl [Levitra®], tadalafil [Cialis®]) and yohimbine (Yohimbine®, Yocon®).
Selective enzyme inhibitors are available by prescription and may be taken up to once a day to treat erectile dysfunction. They improve partial erections by inhibiting the enzyme that causes their reduction.
Patients taking nitrate drugs (for chest pain) and alpha-blockers (for high blood pressure) should not take selective enzyme inhibitors. Common side effects include headache, facial and neck redness, nasal congestion, indigestion, possible hearing loss, ringing in the ears and dizziness. Before taking any medication, discuss the possible side effects with your doctor, as well as any previous health problems, illness, and any medications you are taking.
Hormone replacement therapy
For the small number of men who have testosterone deficiency, testosterone replacement therapy may be an option to treat erectile dysfunction.