The inability to achieve or sustain a sufficiently firm penile erection (tumescence) to allow normal vaginal sexual intercourse. The great majority of cases are not caused by organic disease and most men experience occasional periods of impotence. It is often related to anxiety about performance and is usually readily corrected by simple counselling methods which prescribe sensual massage but forbid coitus. Organic impotence may be caused by DIABETES, MULTIPLE SCLEROSIS, spinal cord disorders and heart disease. Many cases can be helped by the drug SILDENAFIL (Viagra).
Vijay Bhat, MD is a board certified internal medicine physician who is passionate about providing quality medical care that’s affordable for patients. He believes that integrating technology and medicine can make healthcare efficient and more accessible. Throughout his training Dr. Bhat was involved with global health initiatives, providing care to underprivileged communities locally and overseas. He’s also been a strong proponent of quality improvement in the medical field. Dr. Bhat graduated with a BS from the University of California Berkeley, and received his medical degree from Stony Brook University in New York. He completed his residency in Internal Medicine at Rutgers Robert Wood Johnson.
Penile blood flow is measured using a Doppler probe and a 2.5 cm blood pressure cuff. Systolic pressures in the right and left corpora cavernosa are measured and the penile–brachial index is calculated taking a ratio of penile systolic pressure to brachial systolic pressure. These measures should be repeated before and after 3 minutes of exercising the pelvic and leg muscles. In normal men, the PBI should be 0.9 or greater. Ratios between 0.7 and 0.9 suggest vascular impotence; a ratio below 0.6 is diagnostic. Pelvic arteriography can be done if revascularization is considered.
Erection is a vascular event. The penis becomes rigid when blood flow to the corpora cavernosa increases sixfold and venous outflow is physiologically impeded. Penile perfusion is governed by three organ systems—the neurologic, circulatory, and endocrinologic systems—each necessary for potency. The neurologic system accounts for vasodilation and venoconstriction of the corporal blood vessels so that blood is shunted to the erectile tissues; the circulatory system provides adequate blood flow to the hypogastric-cavernous bed, a distal branch off the internal iliac vessels; and the endocrine system, mediated by testosterone, plays a permissive role through mechanisms that have yet to be elucidated.
The penis contains three cylinders, the two corpora cavernosa, which are on the top of the penis (see figure 1 below). These two cylinders are involved in erections. The third cylinder contains the urethra, the tube that the urine and ejaculate passes through, runs along the underside of the penis. The corpus spongiosum surrounds the urethra. Spongy tissue that has muscles, fibrous tissues, veins, and arteries within it makes up the corpora cavernosa. The inside of the corpora cavernosa is like a sponge, with potential spaces that can fill with blood and distend (known as sinusoids). A layer of tissue that is like Saran Wrap, called the tunica albuginea, surrounds the corpora. Veins located just under the tunica albuginea drain blood out of the penis.
Obesity and metabolic syndrome can cause changes in blood pressure, body composition, and cholesterol which may lead to ED. Other conditions that may contribute to erectile dysfunction include Parkinson’s, multiple sclerosis, Peyronie’s disease, sleep disorders, alcoholism, and drug abuse. Taking certain medications can also increase your risk for ED.
Phosphodiesterase inhibitors: This class of medications includes sildenafil, tadalafil, and vardenafil. They work by inhibiting an enzyme called phosphodiesterase type 5 (PDE-5), allowing more blood to enter the penis and helping to produce an erection. These medications are often taken before sex and will cause an erection only when the man is sexually stimulated.
It appears that testosterone has NOS-independent pathways as well. In one study, castrated rats were implanted with testosterone pellets and then divided into a group that received an NOS inhibitor (L-nitro-L-arginine methyl ester [L-NAME]) and a control group that received no enzyme.  The castrated rats that were given testosterone pellets and L-NAME still had partial erections, a result suggesting the presence of a pathway independent of NOS activity.
Parasympathetic input allows erection by relaxation of trabecular smooth muscle and dilation of the helicine arteries of the penis. This leads to expansion of the lacunar spaces and entrapment of blood by compressing venules against the tunica albuginea, a process referred to as the corporal veno-occlusive mechanism. The tunica albuginea must have sufficient stiffness to compress the venules penetrating it so that venous outflow is blocked and sufficient tumescence and rigidity can occur.
In some cases, nocturnal penile tumescence testing is performed to find out whether the man has erections while asleep. Healthy men usually have about four or five erections throughout the night. The man applies a device to the penis called a Rigiscan before going to bed at night, and the device can determine whether he has had erections. (If a man is able to have normal erections at night, this suggests a psychological cause for his impotence.)
Dr Kenny du Toit is a urologist practicing in Rondebosch, Cape Town. He is also consultant at Tygerberg hospital, where he is a senior lecturer at Stellenbosch University. He is a member of the South African Urological Association, Colleges of Medicine South Africa and Société Internationale d’Urologie. Board registered with both the HPCSA (Health professions council of South Africa) and GMC (General medical council UK). He has a keen interest in oncology, kidney stones and erectile dysfunction.http://www.dutoiturology.co.za
Prostate cancer isn’t considered a cause of ED on its own, but radiation treatments, hormone therapy, and surgery to remove the entire prostate gland can lead to difficulty in getting or keeping an erection. Sometimes erectile dysfunction related to prostate cancer treatment is only temporary, but many guys experience ongoing difficulties that need to be addressed by other means.
Concerns that use of pornography can cause erectile dysfunction have not been substantiated in epidemiological studies according to a 2015 literature review. However, another review and case studies article maintains that use of pornography does indeed cause erectile dysfunction, and critiques the previously described literature review.
I am a woman who is currently in menopause. My sex drive has increased and i believe that it can equate to a teenage boy. My s.o. has erection dissatification. He can not penetrate. He prefers oral. He will become erect and orgasm. He works very hard to please me but sometimes I want intercourse. It makes me feel like he isnt attracted to me. I have been with him for quite some time and believe he has always had this problem. I dont understand why. I understand when you say that your wife has no interest. It can be hurtful.