Micturition syncope or post-micturition syncope is the name given to the human phenomenon of

fainting Syncope , commonly known as fainting or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from ...

shortly after or during

urination Urination is the release of urine from the bladder through the urethra in Placentalia, placental mammals, or through the cloaca in other vertebrates. It is the urinary system's form of excretion. It is also known medically as micturition, v ...

. 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. Sometimes defecating,

cough A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and Microorganism, microbes. As a protective reflex, coughing can be repetitive with the cough reflex fol ...

ing, or severe

vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...

may cause fainting in a similar way.

Causes

When one strains to increase the flow of urine, it stimulates the

vagus nerve The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

(usually more pronounced in elderly men with large prostates). The vagus nerve stimulus causes slowing down of the heart (

bradycardia Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due ...

) and a drop in

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

. The heart cannot perform effectively as a pump because insufficient blood comes to it. It can be associated with a very rare tumour known as a paraprostatic pheochromocytoma within the urinary bladder.

Treatment

There is no specific treatment for micturition syncope. General advice to men with micturition syncope includes: * to sit while urinating * to sit on the edge of the bed for a while before getting up and going to the toilet * to avoid urinating while sleepy * to urinate before sleep * to stop urination, cross the legs, and flex them immediately upon feeling faintness

Epidemiology

Responsible for 2.4 to 8.4 percent of all cases of fainting in

adult An adult is an animal that has reached full growth. The biological definition of the word means an animal reaching sexual maturity and thus capable of reproduction. In the human context, the term ''adult'' has meanings associated with social an ...

s, it most commonly occurs in

male Male (Planet symbols, symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or Egg cell, ovum, in the process of fertilisation. A male organism cannot sexual repro ...

s. The events often occur at night or after awaking.

References

{{reflist Urological conditions