Syncope, also known as fainting or passing out, is fairly common. About half the population will probably have one fainting episode in their lifetime.
A recent example that made the news is a video, which shows a woman in Madrid fainting and then actually falling into a subway. Luckily, a bystander was able to get to her quickly.
The majority of the time, fainting is caused by a drop in blood pressure and the person recovers within a few seconds.
Electrophysiologist Tom Wallace says most people who faint have warning signs, such as dizziness, ringing in the ears and nausea.
"It's the patients who don't have the warning symptoms that are concerning. Usually those patients are the ones having life threatening rhythms. Either their heart just stops or pauses for too long or it goes incredibly fast."Dr. Wallace says if you are older and have underlying heart disease, or heart rhythm problems and experience a fainting episode, you should get checked out immediately.
Doctors can perform an EKG or ultrasound to find out if there is a more serious cardiac condition.
Also, patients who lose consciousness immediately without warning signs are at high risk of developing life threatening problems.
Fortunately, most syncope is not cardiac related and can often be prevented.
"Remaining hydrated, eating three full meals a day, being aware of the symptoms and knowing when you have them. You should get your head down and your feet up and then there are also maneuvers like squeezing your hands and crossing your legs. That helps to get blood back up to the brain to prevent you from fainting."
Dr. Wallace says the most important thing is for your doctor to get a full history of your medical condition and make sure and mention specifics as to when you passed out, what was going on at the time and how often. Then a full physical evaluation is critical for proper diagnosis.