A temporary lack of sufficient blood flow to the brain can result in a short loss of consciousness. This situation is referred to as 'syncope' (SIN-ko-pee). Syncope may be brought on by something as simple as a sudden change in body position, heavy sweating, or more complex conditions such as rapid blood pressure changes or various heart and lung disorders. In particular, children and teenagers are occasionally susceptible to a type of fainting spells that are generally harmless. In this form of syncope, brain circulation is reduced due to a drop in blood pressure. Usually, proper blood flow and consciousness can be quickly restored by promptly moving the young person to a reclining position. However, if the child remains in an upright position, the syncope may be prolonged and develop into a seizure. Young people prone to this condition can help prevent these spells by drinking plenty of water, taking in adequate dietary salt, and learning to recognize the dizziness, nausea and sweaty palms that precede such an event. Lying down or putting the head between the knees can generally ward off the episode. In adults, certain variations of a common but serious condition called arrhythmia (ah-RITH-mee-uh) may lead to sudden syncope. In arrhythmia, the heart's normally regular electrical signals malfunction, causing the heart to beat too quickly, too slowly, or irregularly. Fortunately, most forms of arrhythmia are treatable. In general, a person who loses consciousness easily or frequently may require medical evaluation to rule out the more serious causes of syncope. If you're concerned about fainting spells, contact a healthcare provider.