Syncope is a technical term for “passing out”. Over 90% of all situations involving syncope in the adult are related in some way to the cardiovascular system. Fortunately, rarely it is a significant problem. A minor nervous system imbalance is the most common cause and is tested using what is called a tilt study. More serious problems can exist and usually involve rhythm disorders of the heart or significant types of valvular disease. Fainting or syncope is a serious problem in the adult and should be evaluated thoroughly.