It is a condition whose symptoms are as plain as they are debilitating: Migraine.
It affects 1 in 7 people in the UK, and spares no age group, though women are hardest hit.
Such is its reach that the World Health Organization has classified migraine as one of the top 20 most disabling lifetime conditions.
Migraine Awareness Week this year runs from September 4th, its goal to encourage those affected to seek help.
We have compiled an overview of the condition, to help you understand migraine and how it can be managed.
What is a migraine?
The pain caused by a migraine is often described as an intense pulsing or throbbing pain in one area of the head, which can be accompanied by heightened sensitivity to light and sound, as well as nausea and vomiting.
It is sometimes preceded by disturbed vision, or flashing lights and zig zag lines. It can be triggered by any number of things, including including bright or flashing lights, lack of food or sleep, or exposure to light.
In women, migraine is often tied to changes in hormonal levels. Other triggers involve anxiety, stress, or relaxation after stress.
Causes of migraine
For many years, scientists thought migraines were caused by the dilation and constriction of blood vessels in the head.
But current research indicates that migraine may be caused by inherited abnormalities in genes that control certain brain activities.
Scientists hope to identify specific genes that cause migraine pain, which could pave the way for the development of drugs that could prevent or interrupt migraine.
While there is no cure for migraine, there are two ways of managing it, either by preventing the attacks or relieving the symptoms.
A number of drugs developed for other conditions, such as epilepsy, depression or high blood pressure, are now used to prevent the onset of migraine.
When the headache strikes, drugs called triptans are widely used for pain relief.
In women whose migraines are linked to their menstrual cycle, hormone therapy may also bring relief.
In the UK, the neurotoxic protein Botox was licensed in 2010 by the Medicines and Healthcare Products Regulatory Agency as a preventative treatment for adults with chronic migraine. However, its use in the NHS remains limited, as the National Institute for Health and Clinical Excellence has not yet provided formal guidance.
But dealing with migraine can also involve lifestyle changes.
These involve reducing stress by exercising and relaxing, avoiding trigger foods and drinks, eating regular meals, getting enough sleep, losing weight, and modifying the use of medications.