A migraine is usually a moderate or severe headache felt as a throbbing pain on one side of the head.
Many people also have symptoms such as nausea, vomiting and increased sensitivity to light or sound.
Migraine is a common health condition, affecting around one in every five women and around one in every 15 men. They usually begin in early adulthood.
There are several types of migraine, including:
Some people have migraines frequently, up to several times a week. Other people only have a migraine occasionally. It's possible for years to pass between migraine attacks.
Read more about the symptoms of migraine
You should see your GP if you have frequent or severe migraine symptoms.
Simple painkillers such as paracetamol or ibuprofen can be effective for migraine. However, be careful not to take too many painkillers as this could make it harder to treat headaches over time.
You should also make an appointment to see your GP if you have frequent migraines (on more than five days a month), even if they can be controlled with medication, as you may benefit from preventative treatment.
You should call 999 for an ambulance immediately if you or someone you're with experiences:
These symptoms may be a sign of a more serious condition, such as a stroke or meningitis, and should be assessed by a doctor as soon as possible.
Read more about diagnosing migraines
The exact cause of migraines is unknown, although they're thought to be the result of temporary changes in the chemicals, nerves and blood vessels in the brain.
Around half of all people who experience migraines also have a close relative with the condition, suggesting that genes may play a role.
Some people find migraine attacks are associated with certain triggers, which can include:
Read more about the causes of migraines
There's no cure for migraines, but a number of treatments are available to help reduce the symptoms.
During an attack, many people find that sleeping or lying in a darkened room can also help.
Read more about treating migraines
If you suspect a specific trigger is causing your migraines, such as stress or a certain type of food, avoiding this trigger may help reduce your risk of experiencing migraines.
It may also help to maintain a generally healthy lifestyle, including regular exercise, sleep and meals, as well as ensuring you stay well hydrated and limiting your intake of caffeine and alcohol.
If your migraines are severe or you've tried avoiding possible triggers and are still experiencing symptoms, your GP may prescribe medication to help prevent further attacks.
Medications used to prevent migraines include the anti-seizure medication topiramate and a medication called propranolol that's usually used to treat high blood pressure. It may take several weeks before your migraine symptoms begin to improve.
Read more about preventing migraines
Migraines can severely affect your quality of life and stop you carrying out your normal daily activities. Some people find they need to stay in bed for days at a time.
However, a number of effective treatments are available to reduce the symptoms and prevent further attacks.
Migraine attacks can sometimes get worse over time, but they tend to gradually improve over many years for most people.