A very common condition which may vary considerably in severity, type, significance and cause. Most headaches do not represent alarming disease and may merely indicate a common cold or tiredness. However, persistent or recurrent headaches should always be taken seriously. Although the brain itself is insensitive to pain, the surrounding membranes – meninges – are very sensitive, and changes in intracranial arteries, or spasm of the neck or scalp muscles, which may occur for various reasons, may cause considerable pain. In most cases a clinical diagnosis should be possible: further investigations should only be necessary following head injury if headaches recur, or if neurological signs such as drowsiness, vomiting, confusion, seizures or focal signs develop.
Stress and anxiety are probably the most common causes of headache (the medical term is tension headache) and, where possible, the reasons – overwork, family problems, unemployment, financial difficulties, etc – should be tackled. An unpleasant environment, such as traffic pollution or badly ventilated or overcrowded working conditions, may provoke headaches in some people, as may excessive smoking or caffeine intake.
MIGRAINE is a characteristic and often disabling type of recurrent headache. Often there are premonitory signs, called an aura, characteristically some sort of visual disturbance like flickering lights; this is followed by headache that is usually on one side of the head only (migraine comes from hemicrania, meaning half the head). Cluster headaches are particularly severe, migraine-like events with eye watering, which occur several times over a short period and recur intermittently.
High blood pressure may cause headaches (see HYPERTENSION). SINUS infections are often characterised by frontal headaches. Headache, with pain in the jaw on talking, may be due to TEMPORAL ARTERITIS. Eyestrain due to refractive errors of the eyes can cause headache but not so commonly as is generally believed (see EYE, DISORDERS OF). Fewer than 1 in 100 patients referred to hospital clinics with headache have a potentially dangerous condition such as MENINGITIS, brain tumours or SUBARACHNOID HAEMORRHAGE. A danger sign is sudden onset of a first-ever very severe headache which gets steadily worse or, at least, does not improve (‘thunderclap headache’). In such circumstances, admission to hospital for brain imaging by CT or MRI is usually advisable. With recurrent headache, particular concerns include one that worsens at night or in the early morning; ever-increasing headaches; those associated with abnormal neurological signs on examination; or those associated with fits or change in personality or in school or work performance (see FIT). Such sufferers may be advised to have investigations undertaken to determine whether a brain tumour is present.
An often unrecognised cause of headache is overuse of pain killers, classified as use during more than 17 days a month. In nature it is similar to tension headaches.
The initial aim is to obtain a reliable diagnosis by an experienced clinician, taking a careful history and performing a physical examination followed by further investigations if needed (see COMPUTED TOMOGRAPHY (CT) and MRI). Treatment in most cases should then be directed at the underlying condition.
Whether the cause is physical or stress-induced, used sensibly and for a limited period a low dose of aspirin (adults only) or paracetamol may be helpful. In many cases of stress-induced headache, however, the most effective treatment is relaxation. There are many specific treatments for MIGRAINE, such as TRIPTANS, as there are for HYPERTENSION. SINUSITIS is treated with antibiotics and sometimes by surgery. Analgesia-provoked headaches are best dealt with by reducing the drug intake.