The short answer
Almost everyone gets a headache sometimes. The NHS puts it plainly: most headaches go away on their own and are not a sign of something more serious. They can last 30 minutes, several hours, or sometimes several days. The cause is often everyday — stress, too little sleep, dehydration, a cold, or skipping meals — but the pattern of the pain matters. A dull pressure on both sides of the head, a throbbing pain on one side with nausea, and a severe piercing pain around one eye are three very different headaches, and knowing which one you are dealing with helps you know what to do next.
What a headache is
A headache is pain in the head, face, or neck. In the first broad group, the headache itself is the condition — the pain is the problem, not a symptom of another illness. Migraine, tension-type headache, and cluster headache are the main examples. In the second group, the headache is caused by something else, such as a cold or flu, dehydration, or taking too many painkillers. A new, changing, severe, or recurring headache deserves medical attention.
Tension-type headache: the most common kind
Tension-type headache is the everyday headache most people know best. The NHS describes its common symptoms as pain on both sides of the head, face, or neck; a feeling like something is pressing on the head or being tightened around it; and an area that may feel tender. You should usually be able to continue daily activities without making the headache worse. Tension headaches last at least 30 minutes, but they can last much longer, sometimes for several days. Common causes include stress, sleep problems, and caffeine, and taking painkillers too often can itself cause headaches.
Migraine: more than a bad headache
Migraine causes a set of symptoms known as a migraine attack, and it is much more than an ordinary headache. The NHS describes the main symptoms as a throbbing headache, which can be severe, often on one side of the head and worse when you move around; feeling or being sick; and being very sensitive to light and sounds. Early symptoms can start hours or up to two days before the pain, such as tiredness, food cravings, mood changes, or a stiff neck.
Some people get warning signs before an attack, called aura, such as seeing zigzag lines or flashing lights, numbness or pins and needles, dizziness, or difficulty speaking. Aura symptoms should not last longer than one hour. Migraine attacks usually last between four hours and three days, and attacks just before or during a period, called menstrual migraines, are often longer and more severe.
The NHS says it is not known what causes migraine, but it happens when there are changes to nerves and blood vessels in the brain. You are more likely to get it if a close family member has it, and women are more likely to get migraine than men. Common triggers include having your period, anxiety and depression, stress and tiredness, skipping meals, too much caffeine, and not getting enough regular exercise.
Cluster headache: severe, short, and one-sided
Cluster headaches are less common but far more severe. The NHS describes them as severe headaches that can happen multiple times a day and continue for weeks or months. The main symptoms are a sharp, burning, or piercing pain, usually on one side of the head around the eye; headaches at the same time of year or day; headaches that start and stop quickly, without warning; restlessness; and attacks lasting 15 minutes to three hours.
Other symptoms on the same side as the pain can include a red and watering eye, a drooping or swollen eyelid, a smaller pupil, face sweating, and a blocked or runny nose. The NHS says it is not known what causes cluster headaches, and they are more common in men in their thirties and forties. There is no cure, but a specialist may recommend treatments — and ordinary painkillers such as paracetamol and ibuprofen do not work for cluster headaches. Anyone who thinks they might have cluster headaches should see a GP.
Other common causes
Not every headache is a migraine, tension headache, or cluster headache. The NHS lists a cold or flu, stress, too much alcohol, bad posture, eyesight problems, skipped meals, dehydration, taking too many painkillers, and periods or menopause. A headache that arrives with a cold or flu usually settles as the infection clears — our day-by-day guide to how long the flu lasts explains that timeline. Poor sleep is another frequent contributor — see our guide to sleeping well in winter.
Everyday triggers worth noticing
Triggers differ from person to person, but the NHS pages point to the same handful: stress and tiredness, too little or irregular sleep, skipped meals, dehydration, too much caffeine or a sudden cut in it, alcohol, long screen hours with poor posture, and hormonal changes. For migraine, the NHS adds anxiety and depression and not getting enough regular exercise. For cluster headache, it adds smoking, strong smells such as perfume or paint, and exercise. A headache diary — when headaches happen, how long they last, how painful they are, other symptoms, possible causes, and medicines taken — can reveal patterns over a few weeks.
Simple self-care steps
For an ordinary headache, the NHS suggests drinking plenty of water, resting if you also have a cold or the flu, and trying to relax, because stress can make headaches worse. The NHS mentions painkillers such as paracetamol or ibuprofen as an option, and a pharmacist can advise which is suitable for you. Stay at home if you have a high temperature or do not feel well enough for normal activities. Also avoid skipping meals, sleeping more than you usually would, straining your eyes for a long time at a screen, and drinking alcohol.
For migraine, the NHS suggests lying down in a darkened room during an attack, avoiding known triggers, staying hydrated, limiting caffeine and alcohol, eating at regular times, exercising regularly, sleeping plenty, and managing stress. For tension headaches, it suggests relaxing activities such as exercise, yoga and massage, better sleep habits, a low, firm pillow and heat or cold packs for neck pain, and less caffeine. One caution applies across all types: try not to take painkillers for more than two days a week, the NHS advises, because using them too often can cause more headaches.
When to see a doctor: the red flags
Most headaches are not serious, but some need medical help. See a GP if self-treatment is not helping or the headache is getting worse, or if you regularly get headaches. For migraine, also see a GP if attacks are severe, getting worse, lasting longer than usual, happen more than once a week, or are difficult to control.
Ask for an urgent GP appointment or NHS 111 help if a headache comes with vision or eye problems; is triggered or made worse by coughing, sneezing, bending down, or exercising; comes with vomiting; is a child’s headache that is getting worse or wakes them at night; or comes with jaw pain when eating or a sore or tender scalp. For migraine, get urgent advice if an attack has lasted longer than 72 hours, aura symptoms last longer than one hour, or you are pregnant or have just had a baby. In the UK you can call 111 or get help from 111 online, and call 111 for a child under five.
Call 999 or go to A&E immediately if a headache comes with any of these: a seizure; numbness or weakness in the body or face; sudden, extremely painful onset; a head injury within the last three months; difficulty speaking, balancing, walking, or remembering things; drowsiness or confusion; loss of vision; a rash that does not fade when a glass is rolled over it; or a very high temperature, a stiff neck, or bright lights bothering you. Do not drive to A&E — ask someone to drive you or call 999 for an ambulance, and bring any medicines you take. Outside the UK, call your local emergency number.
The bottom line
Headaches are common, and most are not dangerous. Tension-type headache feels like pressure or tightness on both sides of the head, often linked to stress, sleep problems, or caffeine. Migraine is a throbbing, often one-sided pain with nausea and sensitivity to light and sound, lasting four hours to three days. Cluster headache is a severe, piercing pain around one eye lasting 15 minutes to three hours. Rest, water, regular meals and sleep, less alcohol and caffeine, and a headache diary help many people. But a sudden, extremely painful headache, or one with weakness, confusion, vision loss, a seizure, a stiff neck with high fever, or a recent head injury needs emergency help now — and a headache that keeps coming back deserves a GP visit.
This article is for general information only and is not a substitute for medical advice. It cannot diagnose you. If you are worried about a headache, contact a GP, NHS 111, or your local doctor.