Fainting is a temporary loss of consciousness. If you're about to faint, you'll feel dizzy, lightheaded, or nauseous. Your field of vision may "white out" or "black out." Your skin may be cold and clammy. You lose muscle control at the same time, and may fall down.
Fainting usually happens when your blood pressure drops suddenly, causing a decrease in blood flow to your brain. It is more common in older people. Some causes of fainting include
- Heat or dehydration
- Emotional distress
- Standing up too quickly
- Certain medicines
- Drop in blood sugar
- Heart problems
When someone faints, make sure that the airway is clear and check for breathing. The person should stay lying down for 10-15 minutes. Most people recover completely. Fainting is usually nothing to worry about, but it can sometimes be a sign of a serious problem. If you faint, it's important to see your health care provider and find out why it happened.
- Fainting during Urination (Micturition Syncope): What Causes It? (Mayo Foundation for Medical Education and Research) Also in Spanish
- Vasovagal Syncope (Mayo Foundation for Medical Education and Research) Also in Spanish
- Genetics Home Reference: progressive familial heart block (National Library of Medicine)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Fainting (Nemours Foundation)
- Fainting (Syncope) (AGS Foundation for Health in Aging)