Erectile dysfunction (ED) is defined as the persistent inability to achieve and/or maintain an erection for satisfactory sexual function. The incidence of ED cannot be precisely estimated because the proportion of patients who seek medical attention is relatively low.
It is estimated that almost 8–10% of the male population between the ages of 18 to 60 experience this problem. Although not a life-threatening condition, it has serious implications on the quality of life for men.
Compared to the general population, hypertensive patients have a higher prevalence of ED. Hypertension per se, as well as several anti-hypertensive medications are reported to adversely affect erectile function.
The physiology of an erection
The physiological mechanism of penile erection is a complex interaction of neural, vascular, hormonal, and psychological factors. Anatomically, the shaft of the penis contains corpora cavernosa, two chambers that extend from the head of the penis into the pelvis.
The corpora cavernosa contain blood vessels, smooth muscle fibre, and empty spaces. In a normal situation, the arteries supplying blood to the penis are only partially open.
This provides the blood flow needed to keep the tissue healthy. When sexual arousal happens through mental or physical stimulation, the brain sends signals to trigger a hormonal response that allows the arteries to open completely.
Consequently, more blood will enter the corpora cavernosa. The blood enters faster than it can leave through the veins.
The veins will then be compressed, trapping blood in the penis. This reaction helps to achieve and maintain an erection.
When the brain stops sending signals that indicate sexual arousal, the hormonal response ends. The arteries go back to normal and the penis returns to a flaccid state.
How does hypertension affect erection?
Aside from the mechanical process, the dilatation of arteries in general involves biochemical reaction on a cellular level.
Because of that, the most important ingredient for a successful erection is the presence of normal cell lining of the blood vessel and the availability of nitric oxide.
Nitric oxide helps regulate blood vessel tone (the widening or narrowing of blood vessels).
In the case of high blood pressure, reactionary changes occur in the physical structure of the blood vessel. Increased pressure can cause small tears in the vessel walls, and in the process of repairing these tears, the arteries become thicker and narrower, limiting blood flow.
This can restrict blood flow to the penis, which can cause erectile dysfunction. High blood pressure is also responsible for lowering nitric oxide levels.
Nitric oxide is a powerful agent that makes blood vessels relax and dilate. Those with long term hypertension may produce less nitric oxide over time which consequently affects the penile blood vessels ability to dilate sufficiently.
As a result, the extra blood required to fill the penis cannot be delivered which in turn leads to ED. In addition, men with high blood pressure may also have a low testosterone level.
Testosterone is the main hormone in men that plays a big role in sexual arousal. Low testosterone levels will lead to a decrease in hormonal response to arousal.
Anti-hypertensive medication and erectile dysfunction
Anti-hypertensive medication can cause ED as well. Even though there are differences between various drug classes, most anti-hypertensive drugs are associated with at least some degree of ED especially diuretics and beta blockers.
Diuretics may cause ED by decreasing the force of blood flow into the penis. They may also decrease the amount of zinc in the body.
Zinc is needed for the production of testosterone. Fortunately, the effect of diuretics on ED is completely reversible after cessation of administration.
Beta-blockers disturb the response to nerve impulses that lead to an erection. It leads to insufficient relaxation of the corpora cavernosa which make it more difficult for the arteries in the penis to widen and let blood enter.
Beta-blockers can also induce mild sedation or depression that leads to reduced libido or sexual drive. This may cause ED through decreased sexual arousal.
Because the mind also plays a role in erection, psychological factors can contribute to ED as well. The incidence of ED is higher in patients who know of their medication’s side effect than in those who don’t know.
Anxiety in itself can cause ED. The mere knowledge that their medication may aggravate the patient’s pressure to perform in sexual relationship can trigger ED.
Erectile dysfunction in hypertensive patients can be due to vascular changes, medication side effects and may be related to stress or depression.
If you are hypertensive and experience erectile dysfunction know that this is not unusual and do not hesitate to consult your doctor.
This article first appeared in hellodoktor.com and was reviewed by the Hello Doktor Medical Panel. The Hello Health Group does not provide medical advice, diagnosis or treatment.