What does it mean to faint?
Syncope, the medical term for fainting, is very common. About 1 out of every 3 people has it at some point in life. After fainting, a person quickly “comes to” and is OK again. In many cases, syncope is nothing to worry about.
What causes syncope?
Syncope happens when the brain temporarily doesn’t get enough blood. One of the most common reasons this happens is called “vasovagal syncope.” If you have vasovagal syncope, your body has a reaction in which your heart beats too slowly or your blood vessels expand (or both). This can happen for lots of different kinds of reasons. People can have vasovagal syncope if they have stress from fear or pain (for example, because they are injured or have blood taken for tests), stand for too long or are over-tired or overheated, or have an unusual reaction to urinating, coughing, or other body functions.
More often than not vasovagal syncope happens with no clear cause. People can also have syncope that is not vasovagal. This can happen due to the following problems:
The heart beats too quickly or too slowly because of problems with the heart’s electrical system or because of side effects from some medicines.
Something blocks the flow of blood in the heart.
Your blood pressure drops when you stand or sit up. That can happen if you:
- Do not drink enough water
- Take certain medicines that cause your blood pressure to drop
- Drink alcohol
- Lose a lot of blood (for example, if you get hurt)
Is syncope dangerous?
In many cases it is not dangerous. But it can be dangerous if you fall and hurt yourself when you faint. It can also be dangerous if you faint while driving. To be safe, check with your doctor or nurse before you start driving again after you faint.
Should I see a doctor or nurse?
Yes. Anyone who faints should see a doctor or nurse. Most cases of syncope are not serious. But people can get hurt when they faint. Plus, in some cases syncope is caused by a serious medical condition that should be treated. Knowing what caused you to faint can help you prevent it from happening again.
Tell your doctor or nurse what happened before, during, and after you fainted. If someone was with you when you fainted, that person might be able to tell you what happened. The following information is helpful:
What were you doing before you passed out?
How were you feeling before you passed out?
How long were you passed out?
How well did you recover?
Any past history of fainting?
A list of the medicines you take
Any medical conditions you might have
Will I need tests?
Probably not. Many people who faint do not need tests—especially if they faint only once.
If your doctor decides you do need tests, the tests could include 1 or more of the following:
Electrocardiogram (ECG or EKG) – For this test, your doctor will put sticky pads on your chest, belly, arms, and legs. Long, thin wires connect the pads to a machine. The device records the electrical activity in your heart. This can show if the pattern of your heartbeats is abnormal.
Echocardiogram (also called an “echo”) – This test uses sound waves to create an image of the heart.
Home heart monitor – For home monitoring, you might wear or carry a device around at home.
Tilt table test – For this test, you lie flat on a table. Your doctor then monitors your heartbeats and blood pressure while your body is tilted with your head up.
Can syncope be prevented?
You might be able to reduce your chances of fainting again if you learn what causes your syncope. If an activity or condition causes your syncope, you can try to avoid it. If a medicine causes your syncope, your doctor can help you find an alternative. If a heart condition is causing your syncope, your doctor can suggest a treatment. Lay down with your feet up when you feel like you might faint.
How is syncope treated?
That depends on what is causing your syncope. In many cases, the main treatment is to avoid the situations that cause syncope. In less common cases, other treatment might be needed. For example, you might need a pacemaker if your heart beats too slowly and this causes syncope.