Medical Q&As

Fainting - related to alcohol?

On two occasions over the past year I have fainted and my body has gone into spasms. This lasted for about 10 seconds on both occasions. The attacks happened after I had been drinking. I had not consumed any more alcohol than usual. Why did this happen?

This sounds like a simple fainting attack or syncope, to give it its medical name. Fainting is caused by a decrease in blood flow to the brain, which results in temporary loss of consciousness. It would be advisable for you to attend your GP in order to exclude an underlying medical condition however; it is possible that alcohol may have been a factor in the two episodes you describe. Alcohol can cause vasodilatation, which means that the blood vessels in the surface of the skin dilate thereby increasing the volume of blood circulating in the skin. Vasodilatation is the mechanism that produces a flushed appearance to the skin when we drink alcohol. It may also give rise to a reduction in blood pressure, which in turn can reduce the flow of blood to the brain. Other possible causes of fainting include low blood sugar, an irregular heart beat or arrhythmia, various neurological syndromes, prescription drugs, illicit drugs or anxiety attacks leading to hyperventilation. Finally, most people who suffer from simple fainting are quite healthy and have no underlying heart or neurological problem but it would be advisable to have that confirmed by your GP.