Fainting May Run in the Family
A common kind of fainting appears to run in families, a new study of twins shows.
About 1 in 4 people will faint at some point in their lives. Fainting is a sudden, brief loss of consciousness after blood pressure drops to the brain. Sometimes, that loss of blood pressure happens for internal reasons -- dehydration or heart problems, for example.
But puzzlingly, people sometimes black out in response to some kind of outside-the-body trigger, like the sight of blood or after some kind of emotional upset. This is called vasovagal syncope.
Fortunately, fainting isn't usually dangerous. Most people usually wake up a few seconds after they pass out, but they may fall in the process. Falling during a fainting spell, however, can lead to injuries.
The study, which is published in the journal Neurology, suggests that in some cases, fainting may be inherited. If researchers can identify the genes involved, they say it may point to a way to help the small percentage of people who pass out so regularly that it interferes with their lives.