The underlying cause is not fully understood, but it may be a result of vasovagal response, postural hypotension, or a combination thereof.
People often become pale, lightheaded, nauseated, sweaty and weak before they lose consciousness.
When one strains to increase the flow of urine, it stimulates the vagus nerve (usually more pronounced in elderly men with large prostates).
The vagus nerve stimulus causes slowing down of the heart (bradycardia) and a drop in blood pressure.
General advice to men with micturition syncope includes:[2] Responsible for 2.4 to 8.4 percent[citation needed] of all cases of fainting in adults, it most commonly occurs in males.