People sometimes refer to ED as "impotence," although the two aren't really the same condition. ED is the physical inability to develop or maintain an erection that is rigid enough for sex. Impotence is a broader term. While one cause of it is ED, impotence may also involve a lack of sexual desire, an inability to ejaculate, or problems with orgasm.
Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.
To understand what happens in ED, it's helpful to know some anatomical basics. When aroused by either sensory or mental stimuli, the brain sends a signal through the nerves to the penis, causing the muscles there to relax. This opens up space for blood to flow in and engorge the penis. A membrane within the penis traps blood inside to help maintain the erection, which subsides when the penile muscles contract, forcing blood back into the rest of the body. Any number of things can go wrong in this process, leading to erectile dysfunction.
Erections are extremely complicated and surprisingly fragile. Erections involve chemical signals, nerve impulses, complicated blood pressure changes, and overall fitness in systems ranging from your heart and hormones to your mood. When medication changes how one of these factors works—like blood pressure drops or depression medication—ED is a common side effect. The problem with these completely predictable medically induced side effects is how people react.
First of all, libido (sexual desire) triggers a sympathetic (adrenaline-dependent) nervous system reaction mediated through the thoracic spinal cord. Also important is tactile stimulation, the pleasurable effect of touch, which is mediated through the acetylcholine-dependent parasympathetic nervous system. Both the sympathetic and parasympathetic forces regulate the release of nitric oxide—the universal artery-relaxing agent—from the cells lining the penile arteries and all its smaller branches. Nitric oxide causes the arteries to enlarge, increasing blood flow into the penile tissues. This is followed by compression of blood-draining penile veins, which causes blood to engorge the penis and create an erection.4
Although the results provide evidence that PDE5 inhibitors may benefit heart health, the retrospective study design makes it impossible to ascertain direct cause and effect, Andersson noted. It is possible that using erectile dysfunction drugs simply indicates a more active sex life, which could itself contribute to, or be a marker of, a heart-healthy lifestyle overall.
Despite physician’s inexperience and patient’s reluctance to disclose sexual dysfunction problems, attempts to estimate the magnitude of this clinical condition have predicted that over 150 million men worldwide experience some degree of erectile dysfunction. Several studies have demonstrated a wide range regarding the prevalence of erectile dysfunction, which is even higher in patients with essential hypertension where the relative risk is approximately two times higher than in normotensive individuals[6-11]. The etiology can be found in the structural and functional abnormalities of the penile arteries induced by high blood pressure. Smooth muscle hypertrophy, stenotic lesions due to atherosclerosis and impaired blood flow are among the prominent structural alterations whereas endothelial dysfunction and the defective nitric oxide-induced vasodilatory mechanism belong to the main functional abnormalities induced by increased blood pressure[12,13]. As a matter of fact, sexual dysfunction is encountered more frequently that it is indeed believed underlining the need for a more proper and concrete assessment.

In many of these cases, a discussion between the physician, the man with erectile dysfunction, and possibly his partner can help to resolve the issues leading to treatment failure. For men who experience severe side effects, can’t take the drugs for other reasons (such as taking medicines such as nitroglycerin), or don’t respond in spite of further education on the correct use of the drugs, there are other treatment options that can help most men remain sexually active.