Headache: types, causes and red flags

Types of headache

Following the International Classification of Headache Disorders, doctors divide headaches into two broad groups:

• Primary headaches – the headache is the condition itself. These include tension-type headache, migraine and cluster headache.
• Secondary headaches – the headache is a symptom of something else: an infection, head injury, high blood pressure, sinusitis or a medicine side effect, and rarely a bleed, meningitis or a brain tumour.

According to the World Health Organization, headache disorders are among the most common neurological problems worldwide and a major cause of lost work and school days. For more on the nervous system, see our guide to neurological diseases.

Tension-type headache

This is the most common type of headache. Typical features are:

• a pressing or tightening pain on both sides, "like a band" around the head;
• mild to moderate intensity – most people can carry on with their day;
• not made worse by routine physical activity and rarely accompanied by nausea;
• lasting from 30 minutes to several days.

Triggers include stress, tiredness, poor sleep, long hours at a screen, poor posture and missed meals. Regular sleep, exercise, screen breaks, relaxation techniques and, when needed, simple painkillers in sensible doses help. For the chronic form, your doctor may suggest preventive treatment.

Migraine and cluster headache

Migraine is usually a throbbing, often one-sided, moderate to severe pain that worsens with movement and comes with nausea and sensitivity to light and sound. An attack lasts 4 to 72 hours. Around a third of people with migraine have an aura – temporary visual disturbances, tingling or speech problems before the pain. For diagnosis and modern treatment, read our article on migraine.

Cluster headache is less common but extremely painful. The pain is one-sided, around or behind the eye, lasts 15 to 180 minutes and comes with a watering red eye, a blocked nose and restlessness. Attacks come in bouts ("clusters"), often at the same time each day for weeks. It is more common in men. Treatment of an attack includes inhaled oxygen and specific medicines prescribed by a neurologist.

Medication overuse headache

When painkillers are taken too often – typically simple painkillers on more than about 15 days a month, or triptans and combination products on more than about 10 days a month, for several months – headaches can become daily. This is called medication overuse headache.

The answer is to cut back on painkillers under medical supervision, combined with preventive treatment for the underlying headache. The first weeks are often difficult, but headaches usually improve afterwards. If you take other medicines, agree the plan with your doctor rather than stopping suddenly on your own.

Red flags – when a headache is dangerous

Call 112 (or your local emergency number) straight away if:

• the headache is sudden and extremely severe, peaking within seconds to a minute ("like being hit on the head", the "worst ever") – this can be a sign of a subarachnoid haemorrhage;
• it comes with weakness, numbness, a drooping face, slurred speech or loss of vision – possible stroke;
• there is a high temperature, stiff neck, rash, confusion or drowsiness – possible meningitis;
• it follows a head injury, especially if you take anticoagulants;
• there is a seizure or loss of consciousness.

See a doctor within days if:

• the headache is new and you are over 50;
• it has been getting steadily worse over weeks, is worse in the morning or when coughing or straining, and comes with vomiting;
• you are over 50 and have pain in the temple, a tender scalp, jaw pain when chewing or visual disturbance – possible giant cell (temporal) arteritis, which needs prompt treatment;
• you have a weakened immune system or a history of cancer;
• your long-standing headache pattern has changed.

How headaches are diagnosed

Primary headaches are diagnosed mainly through a detailed history and a neurological examination. Your doctor will ask when the headaches started, where the pain is, what it feels like, how long it lasts, what triggers or relieves it and which medicines you take.

A headache diary is very useful: note the date, duration, severity, other symptoms, medicines taken and possible triggers. If you also get dizzy spells, see our article on vertigo and dizziness.

Scans – MRI or CT – are not needed for typical migraine or tension-type headache. They are arranged when there are red flags, abnormal findings on examination or an unusual pattern. If a bleed is suspected, an urgent CT is done, and if meningitis is suspected, a lumbar puncture. Checking blood pressure is part of every assessment.

Treatment and prevention

Treatment depends on the type of headache:

• During an attack – simple painkillers or anti-inflammatory medicines taken early; for migraine, specific medicines prescribed by a doctor.
• Preventive treatment – for frequent or severe attacks, your doctor may suggest daily medicines from several groups and, for migraine, newer treatments targeting CGRP. The aim is fewer and milder attacks.
• Non-drug approaches – regular sleep and meals, enough water, regular physical activity, limiting caffeine and alcohol, stress management, cognitive behavioural therapy and physiotherapy for neck tension.

If you snore heavily and wake with headaches, ask your doctor about possible sleep apnoea. Do not increase painkiller doses on your own.

When to see a doctor

See your GP if you get headaches often (several days a week), take painkillers on more than two or three days a week, if the pain affects your work or sleep, or if your usual remedies no longer help. They can refer you to a neurologist if needed.

Remember: a sudden, extremely severe headache, or a headache with neurological symptoms, high temperature and stiff neck, is an emergency – call 112.

Some patients from Bulgaria seek a neurology consultation or specialist investigations abroad, including at large accredited hospital groups in Istanbul, usually for persistent headaches without a clear cause. If you do, ask for a written report and a treatment plan your own doctor can continue at home. Emergencies should always be treated at the nearest hospital.