A migraine is a recurrent, often severe headache that usually occurs on one side of the head and may be accompanied by symptoms such as nausea and visual disturbances.
The underlying cause is unknown, but it is thought to be due to abnormal brain activity, changes in brain chemicals, and changes in the brain’s blood vessels. Various factors may trigger an attack, including stress, tiredness, low blood sugar, dehydration, bright or flickering lights, caffeine, alcohol, the food additive tyramine, or particular foods, such as cheese or chocolate.
Menstruation, the combined oral contraceptive pill, or hormone replacement therapy may also trigger an attack.
There are two main types of migraines: with aura and without aura. In migraines without aura, there is a headache, usually on one side of the head and typically accompanied by nausea, vomiting, and sensitivity to light and noise.
Migraines with aura causes similar symptoms, but the headache is preceded by warning signs (the aura), such as flashing lights or numbness on one side of the body.
Some people also have very early signs (known as a prodrome), such as mood or appetite changes, before the aura or headache begins.
A migraine can usually be controlled by avoiding triggers, and by medication to prevent or limit attacks or relieve symptoms