Primary ED (ie, the man has never been able to attain or sustain erections) is rare and is almost always due to psychologic factors (guilt, fear of intimacy, depression, severe anxiety) or clinically obvious anatomic abnormalities. Most often, ED is secondary (ie, a man who previously could attain and sustain erections no longer can).
Over 80% of secondary ED cases have an organic etiology. However, in many men with organic disease, ED leads to secondary psychologic difficulties that compound the problem. Psychologic factors must be considered in every case. Psychologic causes may relate to performance anxiety, stress, or a mood disorder (particularly depression).
ED may be situational, involving a particular place, time, or partner. The major organic causes of ED are vascular and neurologic disorders, often stemming from atherosclerosis and diabetes. Complications of surgery, usually prostate surgery, are another common cause. Other causes include hormonal disorders, drugs, and structural disorders of the penis (eg, Peyronie's disease).
The most common vascular cause is atherosclerosis of penile arteries, often secondary to diabetes. Atherosclerosis and aging decrease the capacity for dilation of arterial blood vessels and smooth muscle relaxation, limiting the amount of blood that can enter the penis.
Inadequate impedance of venous outflow (venous leaks) may cause ED or, more commonly, failure to maintain tumescence as long as desired. Venous leaks make it difficult for blood to remain in the penis during erection, so erections occur but cannot be sustained.
Priapism, particularly as in sickle cell disease, may damage penile vasculature and lead to ED. Stroke, partial complex seizures, multiple sclerosis, peripheral and autonomic neuropathies, and spinal cord injuries are among the neurologic causes.
Diabetic neuropathy and surgical injury are particularly common causes. Any endocrinopathy associated with testosterone deficiency (hypogonadism) may decrease libido and cause ED. However, erectile function only rarely improves with normalization of serum testosterone levels."
Recently an article has been published in WebMD describing the health benefits to boost your immune system or maintaining a healthy weight. This is surprising for many people, says Joy Davidson, PhD, a New York psychologist and sex therapist. "Of course, sex is everywhere in the media," she says. "But the idea that we are vital, sexual creatures is still looked at in some cases with disgust or in other cases a bit of embarrassment. So to really take a look at how our sexuality adds to our life and enhances our life and our health, both physical and psychological, is eye-opening for many people."