Erectile dysfunction is a medical condition, also known as 'impotence'. The condition is recognised by the lack of - or reduced - ability to develop or keep an penile erection more than 20% of the time. Its name derives from 'impotentia coeundi', the Latin to describe the inability to insert the penis into the vagina.
The condition is very often a psychological one, and the best solution is to reassess the 'negative thinking' which is currently leading to the problem. Erectile dysfunction can, however, be caused by an underlying medical problem or it can be a side-effect of using certain prescription medication. The best and simplest test for assessing whether a particular episode of erectile dysfunction has a medical or psychological root is simply to note whether the ability to develop an erection has completely ceased - or whether it is still possible during the night, for instance, or in the mornings. If the ability to achieve an erection has not been completely lost, this suggests that the impotence may have a psychological root.
Where impotence has been diagnosed as having an underlying medical cause, there is a still a question of whether the medical cause itself is treatable. Some causes are permanently treatable, others only temporarily, some not at all. Common treatable medical roots of erectile dysfunction include diabetes, hypogonadism (reduced testosterone levels), cardiovascular disease and neuropathy.
In some rare cases, erectile dysfunction can be brought about as a result of regular use of prescription drugs, or undergoing some surgical intervention. In most cases, full erectile function will be restored after the course of medication has ended. Medication which alters the blood flow or testosterone levels may have a negative impact on the ability to achieve or maintain an erection, but this is usually reversible. There have been, however, reports of a condition known as 'Post SSRI Sexual Dysfunction', which is long-term (or occasionally permanent) impotence as a result of using SSRIs.
In cases where the erectile dysfunction is not caused by a treatable medical condition, medical professionals usually prescribe one of the internationally-famous PDE5 Inhibitors developed in the 1990s - of which Viagra and Levitra are just two.