Generally, erectile dysfunction (ED) is a neurovascular condition directly involving the endothelium of the corpora cavernosal arterial blood vessels in the penis, and is indirectly linked to cardiovascular diseases. The underlying mechanisms of ED are, however, complex and involve psychogenic, neurogenic, hormonal and vascular factors. ED occurs in aging men, with a prevalence of 52% in men 40 to 70 years of age [1-3]. Conditions that may cause ED include hypertension, diabetes, diseases of the prostate and heart, and obesity. ED may also be caused by the effects of certain medications as well as physical injury or anatomical deformity of the penis , or may result from endocrine disorders such as low testosterone, hypogonadism, adrenal insufficiency and hypothyroidism. Changes in blood flow to the male reproductive organs as a result of hardening of the arteries or atherosclerosis, hypertension and hypercholesterolemia may result in ED. It is generally accepted that there are vascular and neuropathic components to the pathophysiology of the disease, and ED has been recognized as a potential indicator of underlying cardiovascular disease. Chronic infections and/or inflammation of the prostate and irritation of the bladder may contribute to the pathogenesis of ED.
Classically the neuro-physiology of ejaculation traces the 3 Phases in which ejaculation is a complex event involving the (I) the propulsion of sperm and seminal plasma into the prostatic urethra which is accompanied by (II) bladder neck closure and (III) coordinated contractions of the bulbocavernosus and ischiocavernosus muscles, striated muscles of the pelvic floor, lower limbs and trunk. In the Asian Society of the Aging Male Study  63% have reduced erection, 68% reduced or absent ejaculation and 19% pain or discomfort at ejaculation. Disorders of ejaculation can be due to: (I) disorders of production of sperm or seminal plasma/prostatic secretions (II) disorders of propulsion. In the case of anejaculation (absence of ejaculatory) which is the ultimate disorder of ejaculation, the causes can be best classified as (I) primary or secondary. After covering psychogenic causes of ejaculation failure, the organic causes due to non-dynamic and obstructive etiologies in the prepubertal and post pubertal male will be highlighted. More details will be given on retarded ejaculation, premature ejaculation, aspermia, painful and weak (poor propulsive force) ejaculation. The evaluation of the patient must include a detailed history taken from the patient and often his partner. Aside from haematologic tests, various forms of radiological and ultrasonic imaging, neurophysiologic studies may be required. For the general practitioner the commonest scenario will be in the ED Clinic with abundant men with performance anxiety presenting with premature ejaculation. In the male aging clinic lack of arousal is the commonest cause of retarded orgasm and ejaculation but this group is plagued by decreased touch sensitivity, the need for more direct stimulation, reduced drive to orgasm, a less intense orgasm, ejaculation being weaker and of reduced quantity and disturbing complaints of a longer recovery period and less number of attainable orgasms per day or week. Thus it is not mere rumor that “by the time a man reaches 55, the refractory period to ‘do it again for a man’ increases to 12 hours or even up to a week”. In the STD clinic, painful or bloody ejaculation is frequently seen. The Condom may cause condom retarded orgasm/ejaculation.
Much of the evidence shows high rates of vitamin D deficiency in patients with erectile dysfunction. In fact, one study of 3,400 participants found that men with vitamin D deficiency were 32% more likely to have trouble with erections when all other risk factors were controlled for. It’s a little on the nose that you need vitamin D for your “D,” but hey—science can be funny too.
For a male, sexual performance carries an identity and the sense of self-esteem in his society. Thus, Sexual performance in the male has an unprecedented importance depending on the erectile function of the male sex organ. In daily life, it is very easy for men to admit having a sore throat or hemorrhoids. However, admitting to having erectile dysfunction is contrary to the male ego and especially so if the dysfunction occurs when he is at mid-life and is getting older and there any suspicion of him entering the phase of male menopause.
Tongkat Ali (Eurycoma longiflora) (Figure 7): this native plant found through SE Asia is used as an Aphrodisiac since 1996 (5). It has to be used regularly and works by enhancing the testosterone and cGMP production. Benefits are felt gradually over a period of time, mainly because it enhances the natural biological synthesis of testosterone. When the level is increased, health and vitality are restored. In studies on Mice, Tongkat Ali increases the number of times and duration of sexual performance of the animals under study (8) with testosterone levels increasing up to 440% in some animals. In a recent study on humans, 62% of subjects showed an increase of the free testosterone index indicating it’s biostimulatory effect on steroidogenesis. It has also been shown to increase sperm concentration and motility and increases energy in the individual by enhancing ATP production by 60% thru oxidative phosphorylation.
Arginine. The amino acid L-arginine, which occurs naturally in food, boosts the body's production of nitric oxide, a compound that facilitates erections by dilating blood vessels in the penis. Studies examining L-arginine's effectiveness against impotence have yielded mixed results. A 1999 trial published in the online journal BJU International found that high doses of L-arginine can help improve sexual function, but only in men with abnormal nitric oxide metabolism, such as that associated with cardiovascular disease. In another study, published in 2003 in the Journal of Sex & Marital Therapy, Bulgarian scientists reported that ED sufferers who took L-arginine along with the pine extract pycnogenol saw major improvements in sexual function with no side effects. Arginine can be helpful, says Geo Espinosa, ND, director of the Integrative Urological Center at NYU Langone Medical Center. Espinosa says that men with known cardiovascular problems should take it only with a doctor's supervision; L-arginine can interact with some medications.
Yohimbe A number of clinical trials have shown that the primary component of this bark from an African tree can improve sexual dysfunction associated with selective-serotonin reuptake inhibitors (SSRIs) used to treat depression. This herb has been linked to a number of side effects, including increased blood pressure, fast or irregular heartbeat, and anxiety. Yohimbe shouldn't be used without a doctor's supervision.