Most headaches are not dangerous, but a few patterns need urgent assessment.
See a doctor if
- The headache is sudden and severe — 'the worst headache of my life'
- It comes with fever, neck stiffness or a rash
- It comes with weakness, numbness, confusion or difficulty speaking
- It follows a head injury
- It is new and persistent in someone over 50
- It wakes you from sleep, or is consistently worse in the morning
Common causes
These are causes doctors commonly see. This list cannot tell you which one applies to you.
- Tension headache — a tight band-like pain, the commonest type
- Migraine — often one-sided and throbbing, with nausea or light sensitivity
- Dehydration and skipped meals
- Eye strain and uncorrected vision problems
- Sinus infection
- Overuse of painkillers, which itself causes headaches
- Very high blood pressure, though this is uncommon
Frequently Asked Questions
When is a headache dangerous?
Seek urgent help if it is sudden and severe — the worst headache of your life — or if it comes with fever and neck stiffness, weakness, numbness, confusion or difficulty speaking. Also if it follows a head injury, is new and persistent in someone over 50, or wakes you from sleep.
How do I tell a migraine from a tension headache?
A tension headache is typically a tight band-like pain across the head and is the commonest type. A migraine is often one-sided and throbbing, and usually comes with nausea, or sensitivity to light and sound. Migraine also tends to stop you functioning in a way tension headache does not.
Can taking too many painkillers cause headaches?
Yes. Medication-overuse headache is a well-recognised problem: taking painkillers frequently for headaches can itself cause a persistent headache. If you are reaching for tablets most days, that is worth discussing with a doctor rather than increasing the dose.
What to do next
Note when the symptom started, how it has changed, and anything that makes it better or worse. Take that information — and a list of your medicines — to your doctor. It makes the consultation considerably more useful than trying to recall it on the spot.
If any of the warning signs above apply to you, do not wait for an appointment. Go to a hospital, or call 112.