Treatment for fainting (syncope) will depend on the type of fainting and whether there's an underlying cause.
If someone you're with has fainted and they haven't regained consciousness within one or two minutes, put them into the recovery position.
After putting them into the recovery position, dial 999, ask for an ambulance, and stay with them until medical help arrives.
When you visit the GP after a fainting episode, they'll investigate the type of fainting you experienced and whether there's an underlying cause.
If an underlying cause is found, treating it should help prevent further fainting episodes.
Read more about diagnosing fainting.
Most fainting episodes are associated with a temporary malfunction of the autonomic nervous system, which regulates the body's automatic functions, such as heartbeat and blood pressure.
This type of fainting is called neurally mediated syncope. Treatment for neurally mediated syncope involves avoiding any possible triggers.
If you're not sure what caused your fainting episode, your GP may suggest keeping a diary of any symptoms you experience.
It may help to identify possible causes by making a note of what you were doing at the time you fainted.
There are also steps you can take to avoid losing consciousness if you think you may be about to faint.
Fainting can occur when an external trigger, such as a stressful situation, causes a temporary malfunction in your autonomic nervous system. This is called vasovagal syncope.
In most cases of vasovagal syncope, further treatment isn't required. However, you may find it useful to avoid potential triggers, such as stress or excitement, hot and stuffy environments, and long periods spent standing.
If you know injections or medical procedures like blood tests make you feel faint, you should tell the doctor or nurse beforehand. They'll make sure you're lying down during the procedure.
Fainting can occur when a bodily function or activity – such as coughing – places a sudden strain on the autonomic nervous system. This is called situational syncope.
There's no specific treatment for situational syncope, but avoiding the triggers may help. For example, if coughing caused you to faint, you may be able to suppress your urge to cough and avoid fainting.
Carotid sinus syndrome is where pressure on your carotid sinus causes you to faint. It's more common in older men.
Your carotid sinus is a collection of sensors in the carotid artery, which is the main artery in your neck that supplies blood to your brain.
You can avoid fainting by not putting any pressure on your carotid sinus – for example, by not wearing shirts with tight collars.
In some people, carotid sinus syndrome can be treated by having a pacemaker fitted. A pacemaker is a small electrical device that's implanted in your chest to help keep your heart beating regularly.
Fainting can occur when your blood pressure drops as you stand up. This drop in blood pressure is called orthostatic hypotension.
Avoiding anything that lowers your blood pressure should help prevent fainting. For example, avoid becoming dehydrated by increasing your fluid intake.
Your GP may also advise you to eat small, frequent meals rather than large ones, and increase your salt intake.
Taking certain medications can also decrease blood pressure. However, don't stop taking a prescribed medication unless your GP or another qualified healthcare professional in charge of your care advises you to do so.
Read more about treating low blood pressure.
Physical counterpressure manoeuvres are movements designed to raise your blood pressure and prevent you losing consciousness.
One study found training in physical counterpressure manoeuvres can reduce fainting in some people.
Physical counterpressure manoeuvres include:
You need to be trained to carry out these movements correctly. You can then do them if you experience any symptoms that suggest you're about to faint, such as feeling lightheaded.
If you've fainted, it could affect your ability to drive. Depending on what caused you to faint and whether you have any underlying health conditions, you may need to inform the Driver and Vehicle Licensing Agency (DVLA).
It's your legal obligation to inform the DVLA about a medical condition that could affect your driving ability. The GOV.UK website has more information about blackouts, fainting and driving.
If you've fainted, it may affect your safety at work or the safety of others. For example, continuing to operate machinery may be dangerous if it's likely you'll faint again.
The healthcare professionals who diagnose and treat your condition can tell you whether it's likely to affect your work. If it is, speak to your health and safety representative.