When a headache needs urgent care

Most headaches, even severe ones, are painful but not dangerous. A few signs mean you should get help the same day, and a few mean calling 999. Here's how to tell the difference.

What matters more than how bad it hurts

Most headaches come from a headache disorder such as migraine or tension-type headache, not from another illness. Serious causes of headache are rare. When they happen, the clues are usually in how the headache started, what comes with it and how it differs from your usual headaches. How much it hurts matters less. A severe migraine can hurt more than a dangerous headache.

Call 999 or go to A&E if you have:

• A sudden, severe headache that reaches its worst within a few minutes, often described as the worst headache ever. This can be a sign of bleeding on the brain.
• Weakness or numbness on one side, a drooping face, slurred speech or sudden confusion. These are signs of a stroke.
• A headache with fever and a stiff neck, especially with dislike of light or a rash that doesn't fade when you press a glass against it. This can be meningitis.
• A headache after a head injury that gets worse, or comes with drowsiness, being sick or confusion.
• A fit, a blackout or difficulty staying awake.
• A painful red eye with blurred vision or halos around lights. This can be acute glaucoma, which needs treatment at A&E or an eye casualty unit straight away.

If you're pregnant and have a severe headache with problems with your sight or sudden swelling of your face, hands or feet, contact your midwife or maternity unit immediately. After 20 weeks this can be a sign of pre-eclampsia.

Call NHS 111 or get a same-day GP appointment if:

• You're over 50 with a new headache, especially with a tender scalp around the temples, jaw pain when chewing or changes in your vision. This can be giant cell arteritis, which needs treatment quickly to protect your sight.
• Your headache is getting steadily worse over days or weeks.
• It's worse lying down or first thing in the morning and comes with being sick, or it's brought on by coughing, sneezing or straining.
• It's much worse when you stand up and eases when you lie down.
• You have a new headache and a weakened immune system, or have had cancer.

Think about carbon monoxide. Carbon monoxide poisoning causes headaches that are better when you're away from home. Suspect it if other people in the house, or pets, are unwell too. Get into fresh air, call the Gas Emergency line on 0800 111 999 and see a doctor.

Book a routine GP appointment if:

• the pattern of your headaches has changed
• you have headaches on more days than not
• you're taking painkillers on more than a few days a week, which can itself cause headaches (see our guide The headache that headache pills give you)
• your headaches are affecting your work, sleep or family life

If you already have migraine

Migraine attacks can be frightening, but your usual attacks, even bad ones, don't need emergency care. What matters is something new: a headache that is different from your normal attacks, the worst you've ever had, or new symptoms such as weakness, or aura that lasts longer than an hour.

Knowing what your usual attacks look like makes it easier to spot when something is different. A headache diary gives you, and anyone treating you, that picture.

Know your normal.The free Migrevention diary builds a record of your usual attacks, so changes stand out.

Get the free diary

This guide is general information and doesn't replace medical advice. If you're worried about a headache, trust your instinct and get help.

Sources: NICE CG150, Headaches in over 12s: diagnosis and management. NHS: Headaches. NHS: Giant cell arteritis. NHS: Meningitis. NHS: Carbon monoxide poisoning.