Syncope

Syncope is an involuntary body response that causes fainting. During syncope, the heart rate slows and the blood vessels dilate, which means less blood gets to the brain. A child who is about to faint may feel:

Dizzy or lightheaded
Nauseous
Vision whites out or blacks out

Syncope can be caused by a variety of situations, such as:

Vasovagal syncope
Orthostatic hypotension (standing up too fast)
Heart defects
Irregular heartbeat
Inflammation of heart muscle (myocarditis)

Treatments include avoiding situations that may cause a vasovagal response, such as scary or stressful events. Other treatments include treating any underlying conditions that may cause syncope, such as repairing a heart defect.