Anatomy of a headache

All of us suffer from headaches, some every day. But not all are caused by 'tension'. Kate Watson-Smyth examines the different types - and the surprising variety of triggers.

Rebound

This is a common form of headache that is often overlooked by doctors. It is usually started by over-the-counter painkillers which the sufferer takes in increasing dosages when they fail to work the first time.

As the drug wears off, it simply triggers another headache. Taking these types of pills more than three times a week can greatly increase the chances of such a rebound headache.

Cluster

These are very rare and cause less than one per cent of all headaches. They are also known as the 'alarm clock headaches' as they can occur at exactly the same time every day.

Cluster headaches can happen at least two or three times a day for a couple of months and then disappear again. They are usually around one eye, where there will also be redness and the eye may start watering. More common in men, they can be cured with a course of drugs.

Migraine

These affect one in five women and one in 15 men in the UK. Between 10 and 30 per cent of migraine sufferers will also be affected by aura - visual distortions, such as flashing lights.

The pain is pulsating and can last between four and 72 hours. It is made worse by movement and sufferers often find light and noise intolerable.

Although triggers vary from person to person, the pain always starts when something - often food, weather conditions or stress - causes the blood vessels in the brain to dilate and contract suddenly. Migraines can strike at any age, but typically start in teenage years, or as a young adult.

Tension

The so-called 'normal' headache, which is usually felt all over the head and typically feels like a tight band.

Nine out of ten headaches fall into this category and are triggered by stress and fatigue, which means they often strike in late afternoon. They are caused by the muscles contracting around the skull.

Secondary

Eye strain, often caused by spending long periods staring at a computer screen or not wearing your glasses as much as you should, is commonly cited as a cause of these headaches, but this is not entirely true, according to Dr Giles Elrington, a consultant neurologist at St Bartholomew's Hospital and the London Clinic.

The person who does these things and then has a headache is already prone to them and the environmental factor has acted as a trigger. Sinusitis and toothache can also cause them.

Hangover

This type of headache has similar symptoms to migraines - light sensitivity and pain that is alleviated if the sufferer lies still - but it is, of course, entirely self-inflicted and caused by a lack of sleep, dehydration, and chemicals found in alcohol.

It is cured by rest, rehydration and abstaining from drinking. Aerobic exercise is also an effective cure, but there are few people well enough to try.

Aneurysm

This is characterised by sudden, intense pain that builds up in just a few seconds and can be accompanied by vomiting.

An aneurysm, which can be fatal, is caused by a ruptured blood vessel near the junction with an artery and causes the brain to fill with blood. It usually affects people over 70, smokers and those with high blood pressure.