Symptom guide
Headache
Most headaches are benign tension-type or migraine and resolve with rest, hydration, and over-the-counter analgesics. A small minority are signals of something serious and need urgent assessment — this page helps you tell the difference.
When to seek emergency care
- Sudden "worst headache of your life", often described as thunderclap.
- Headache with fever, stiff neck, or rash.
- Headache with new weakness, numbness, vision loss, or speech changes.
- Headache after a head injury.
- Headache that progressively worsens over days or weeks.
Safe self-care at home
- Drink water — mild dehydration is a common headache trigger.
- Rest in a dark, quiet room for 30–60 minutes.
- Apply a cool cloth to your forehead or the back of your neck.
- Consider an over-the-counter analgesic only if you have taken it safely before; do not exceed the package dose.
- Limit screen time and avoid skipping meals.
When to see a clinician
- Your headache is the worst you have ever had or came on in seconds.
- Headaches are becoming more frequent or more severe.
- Over-the-counter medicine is not helping after 2–3 days.
- You are pregnant and develop a new, severe headache.
Frequently asked questions
Is a daily headache normal?
No. Chronic daily headache (more than 15 days a month) is worth discussing with a clinician — common causes include medication overuse, stress, tension, poor sleep, or dehydration, but persistent headaches should always be evaluated.
Can dehydration really cause a headache?
Yes. Even mild dehydration can trigger a dull, throbbing headache in many people. Rehydrating and resting in a quiet environment typically helps within an hour.
What is a thunderclap headache?
A thunderclap headache reaches peak intensity within 60 seconds and is one of the strongest red flags in medicine. It can indicate a brain bleed and needs emergency assessment immediately.
Are migraines the same as bad headaches?
No. Migraines are a distinct neurological condition that usually involve throbbing pain on one side of the head, sensitivity to light and sound, and sometimes nausea or visual aura.
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Ask about headacheThis page is general patient education aligned with WHO, CDC, and NHS public guidance. It is not a diagnosis, prescription, or substitute for care from a licensed clinician. If symptoms are severe, worsening, or you are in doubt, contact a healthcare provider or your local emergency number immediately.