Headache: Types and Causes

Most headaches are not caused by a dangerous condition, but symptom wording alone cannot provide reassurance. Clinicians assess onset, duration, associated symptoms, age, medicines and health context before deciding whether a headache fits a primary pattern or needs investigation.

Headache is a symptom Headache means pain felt in the head, face or upper neck. It can arise from several pain sensitive structures inside and outside the skull. Brain tissue itself has no pain receptors. However, the coverings around the brain, blood vessels, scalp, muscles, eyes and other nearby structures can generate pain signals. This does not mean that pain location identifies the affected structure. Different headache disorders can produce pain in similar places. Primary and secondary headaches A primary headache is a headache disorder in its own right. Tension type headache, migraine and cluster headache are examples. A secondary headache is caused by another condition or exposure. Examples include an infection, a medicine effect, head injury or a blood vessel problem. Primary headaches are common, while serious secondary causes are uncommon. Clinicians still check for warning patterns because the required action can differ greatly. Common primary headache patterns Tension type headache commonly causes pressing or tightening pain on both sides of the head, face or neck. It is usually mild or moderate and is not worsened by routine activity. Migraine commonly causes moderate or severe headache that may be one sided or affect both sides. It may throb, worsen with movement, and occur with nausea or sensitivity to light or sound. Some people experience migraine aura. Typical aura symptoms develop gradually over at least five minutes, are fully reversible and last between five and sixty minutes. Aura may involve visual changes, pins and needles, numbness or speech disturbance. Sudden or persistent neurological symptoms should not be assumed to be migraine aura. Cluster headache is rare. It causes severe or very severe one sided pain around the eye, usually lasting fifteen minutes to three hours. During a cluster headache, the person is often restless. The eye may become red or watery, while the eyelid may swell or droop on the same side. These are typical patterns rather than diagnostic rules. Headache features overlap, and a clinician considers the complete pattern before naming the disorder. Common contributors and secondary causes Viral illness, dehydration, missed meals, poor sleep, alcohol and stress can contribute to headache. Their presence does not prove the cause. Sinusitis can cause facial pain or headache alongside nasal blockage or discharge. Recurrent headache without clear nasal symptoms should not automatically be labelled a sinus headache. High blood pressure usually causes no symptoms. Headache should not be attributed to ordinary hypertension without checking the wider clinical picture. Medication overuse headache can develop or worsen when acute headache medicines are used frequently for at least three months. The relevant frequency depends on the medicine. NICE highlights use on at least ten days each month for triptans, opioids or combination painkillers. The threshold is fifteen days for paracetamol, aspirin or non steroidal anti inflammatory medicines. Do not stop a prescribed medicine without advice. A clinician can review whether medicine use is contributing and plan changes safely. Warning patterns change the urgency A thunderclap headache is a sudden severe headache that typically reaches maximum intensity within one to five minutes. It requires immediate emergency assessment. Subarachnoid haemorrhage is one serious possible cause of thunderclap headache. Most thunderclap headaches are not caused by this bleeding, but urgent investigation remains necessary. Headache with sudden weakness, numbness, speech difficulty, vision loss, confusion, reduced consciousness or a seizure can indicate a stroke or another neurological emergency. Meningitis can cause a worsening severe headache with fever, neck stiffness, sensitivity to light, vomiting, confusion or unusual sleepiness. A rash may be absent. Giant cell arteritis mainly affects people aged over fifty. New headache with scalp tenderness, jaw pain while chewing, double vision or vision loss needs urgent assessment. Acute angle closure glaucoma can cause headache with intense eye pain, a red eye, blurred vision, coloured haloes, nausea or vomiting. Sudden symptoms are an emergency. During pregnancy or in the weeks after birth, a severe persistent headache can indicate pre eclampsia. Visual symptoms, rib pain, vomiting or sudden swelling increase concern. Age and context matter A new or substantially changed headache deserves assessment, especially with cancer, reduced immunity, recent head injury or unexplained vomiting. Headache triggered by coughing, straining or exercise also needs review. A headache that changes with posture can provide an important clue. In adults, waking with headache or being woken by pain is not specific when considered alone. Children follow age specific pathways. A child under twelve needs same day assessment for a worsening headache, vomiting, balance problems, morning headache or pain that wakes them. Headache within five days of a head injury also needs same day assessment in a child under twelve. Any headache in a child under four needs urgent medical assessment. Examination provides clues A clinician checks blood pressure, temperature, alertness and neurological function. They may assess strength, sensation, speech, coordination, walking and eye movements. The eyes may be examined for optic disc swelling, called papilloedema, or for signs of an eye emergency. The neck, scalp and temples may also be assessed. A normal neurological examination does not exclude every serious cause. In particular, a person with thunderclap headache still needs emergency assessment when the examination is normal. Tests answer specific questions Most people with a recognised primary headache pattern and no concerning features do not need brain imaging. NICE advises against imaging solely for reassurance after a primary headache diagnosis. Suspected subarachnoid haemorrhage is assessed urgently in hospital. A non contrast CT head scan is usually the first imaging test. The timing and interpretation of the CT head scan matter. Further specialist assessment or another test may be needed when the scan does not explain a concerning presentation. Blood tests may support assessment for infection, inflammation or another suspected cause. They do not identify every headache disorder by themselves. A headache diary can record frequency, duration, severity, associated symptoms, medicines and possible triggers. NICE suggests recording for at least eight weeks when using a diary to support diagnosis. What may happen after assessment A familiar primary headache pattern without warning features may be managed without imaging. The plan depends on the headache type, frequency, impact and suitability of treatments. Arrange a GP review if headaches keep returning, occur several times each week, become more severe or change substantially. Review is also appropriate when usual measures stop helping. Seek advice if you use acute headache medicines frequently. Increasing painkiller use can worsen headache and may require a planned medication review. When to get help Call 999 or go to A&E now for a headache that starts suddenly and is extremely painful. Do not drive yourself to A&E. Also call 999 for headache with weakness, numbness, speech or memory problems, loss of vision, confusion, drowsiness, a seizure or recent significant head injury. Call 999 or go to A&E if headache occurs with a very high temperature, stiff neck, marked light sensitivity or a non fading rash. Do not wait for every meningitis symptom or a rash to appear. Call 999 or go to A&E for sudden intense eye pain with a red eye, blurred vision or coloured haloes. A new drooping eyelid or unequal pupils with severe headache also needs emergency assessment. Ask for an urgent GP appointment or contact NHS 111 for severe headache with jaw pain while eating, scalp tenderness, blurred vision or double vision. These can be features of giant cell arteritis. If you are pregnant or gave birth in the last few weeks, seek urgent help for a severe persistent headache. Contact your maternity unit, or call NHS 111 when it is unavailable. This lesson explains headache patterns and assessment. It cannot diagnose an individual headache or replace urgent medical care.

Headache descriptions provide clues rather than diagnoses. Clinicians combine the timing, full symptom pattern, examination and relevant context before deciding whether reassurance, review or urgent investigation is needed.