Often dismissed as stress or dehydration, fainting can be the heart's first warning sign. Cardiologists caution that ...

Add Yahoo as a preferred source to see more of our stories on Google. Where is a fainting couch when you need one? Michael C. Gray/From www.shutterstock.com Over one million Americans faint every year ...

Fainting at the sight of blood is common to many people and usually occurs without warning. Again, it is unrelated to fear or squeamishness; rather, it involves elaborate physiological mechanisms.