Micturition syncope

Micturition syncope or post-micturition syncope is the name given to the human phenomenon of fainting shortly after or during urination.

People often become pale, nauseated, sweaty and weak before they lose consciousness. Sometimes even defecating, coughing or severe vomitting may cause fainting in a similar way.

Epidemiology
Responsible for 2.4 to 8.4 percent of all cases of fainting in adults, it most commonly occurs in males. The events often occur at night or after awaking (this means that it occurs while standing immediately after being recumbent for some time).

Causes
When one strains to increase the flow of urine it stimulates the vagal nerve (usually more pronounced in elderly men with large prostates). The vagal nerve stimulus causes slowing down of the heart (bradycardia) and severe drop in blood pressure. The heart cannot perform as a pump effectively because insufficient blood comes to it.

Treatment
There is no specific treatment for micturition syncope. General advice to men who have a micturition syncope is to sit while urinating, and to sit on the edge of the bed for a while before getting up and going to the toilet.