Fainting, or passing out, is a temporary loss of consciousness from a sudden decrease of blood flow to your brain. An episode usually lasts a few seconds or minutes. Most are harmless, but if you faint often or have other symptoms, you should seek medical attention.
Fainting is a short-term loss of consciousness. It happens because of a sudden drop in blood flow to your brain. A fainting episode usually lasts a few seconds or minutes. Then, you wake up and return to normal.
Other names for fainting are:
Signs you’re about to faint may include feeling:
In addition, you may:
For a few hours after fainting, you may feel tired or just not quite right.
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The most common reason for fainting is a sudden drop in blood pressure, which reduces blood flow and oxygen to your brain. There are many reasons why a drop in blood pressure could lead to a temporary loss of consciousness:
You may faint because of:
Things you do with your body that can make you faint include:
A healthcare provider can work with you to determine the cause of your fainting. They can provide treatment if you need it.
People — often age 65+ — who faint when they stand up too quickly may need:
If a diagnosed heart issue made you faint, a provider may recommend:
People with carotid sinus syncope may need:
If fainting isn’t a frequent problem, many people don’t need treatment beyond what you can provide yourself.
If someone loses consciousness:
When someone faints and then wakes up:
Fainting can happen again in people who have untreated fainting causes.
People who faint because of low blood pressure when they stand up (orthostatic hypotension) may be at risk of injury from falling when they faint.
Cardiac syncope is a sign that you may have a heart issue that can be fatal. You may have an abnormal heart rhythm or an issue with a part of your heart, such as a valve. Without treatment, people who have cardiac syncope are at least twice as likely to have a car accident as the general population.
Yes, you can prevent fainting when you know what causes you to faint. Pay attention to specific activities or situations that make you faint. For example, if getting up too quickly sometimes makes you faint, learn to take your time standing up. You can also move your legs to help your blood move before you stand up.
If you notice how you feel just before you faint, you can try certain strategies to prevent it:
If you faint once and are in good health otherwise, you probably don’t need to talk to a healthcare provider. But seek medical attention if you:
Fainting usually isn’t a sign of a serious health issue, but it can be. Talk to a healthcare provider if you faint and have any of the following symptoms:
Also, report any loss of consciousness to a healthcare provider if you:
A note from Cleveland Clinic
Fainting, or passing out, usually happens because of a drop in blood pressure, which reduces blood flow and oxygen to your brain. Most fainting spells are nothing to worry about. But talk to a healthcare provider if you lose consciousness repeatedly or have any other symptoms. Finding the cause can help you take action to prevent future fainting spells.
Last reviewed by a Cleveland Clinic medical professional on 03/14/2023.
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