Whether you call it passing out or having “a spell,” fainting is an unexpected scare that will happen to nearly one in three people at least once in their life. Although it’s common and people usually regain their consciousness quickly with no more damage than feeling a little disoriented and shaken up, fainting can be a sign of a more serious health condition.
So, what causes a person to faint? When there’s a sudden drop in blood pressure – say from standing up too quickly after lying down, being dehydrated or taking certain medications (e.g., blood pressure, depression, allergies) – blood flow to the brain is decreased.
This can trigger a loss of consciousness and muscle control, which causes the fall to the ground. Signs that you may be close to fainting include:
- “Blacking out” – loss of vision
Some people faint at the sight of blood, or from some type of emotional stress or trauma. This type of fainting is the most common and is caused by a reaction in the brain, when the vagus nerve – the nerve that extends from the brain to the stomach – is overstimulated.
The use of alcohol, narcotics and antistamines can also cause you to pass out. Low blood sugar may also trigger an episode.
More serious, though less common, causes of fainting are problems with your heart that block the flow of blood and oxygen.
You are at an increased risk of fainting if you have any of these conditions:
- heart blockages
- irregular heartbeat (arrhythmia)
- anxiety or panic attacks
What to do if you faint
If you only had an isolated fainting incidence and are in pretty good health, there is little cause for concern. If you are having multiple fainting episodes, you should see your doctor or cardiologist to test if there’s an underlying medical condition. Treatment will depend on the doctor’s diagnosis.