Merck Manual

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Quick Facts

Overview of Headache


The Manual's Editorial Staff

Last full review/revision Aug 2019
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Headaches are one of the most common reasons people go to the doctor.

  • Many things can cause a headache

  • Most headaches aren't dangerous. but some are caused by a serious problem

  • Tension headache and migraine are the two most common types of headaches

  • Problems with your sinuses, brain, or eyes may also cause a headache

  • Often, the doctor just needs to examine you, but sometimes you'll need tests such as a CT scan or a spinal tap

What causes a headache?

The most common causes of headache are:

Other causes of headache are:

When should I see a doctor for a headache?

See a doctor right away if you have a headache and any of the following warning signs:

  • Changes in your vision, weakness, drowsiness, confusion, loss of balance, or trouble speaking

  • A fever and stiff neck

  • A sudden, very severe headache that came on like a thunderclap

  • Tenderness at your temple (as when combing hair) or jaw pain when chewing

  • Cancer, AIDS, or a weak immune system

  • A worsening headache

  • Red eyes and halos seen around lights

See a doctor within a week if you have:

  • Headaches that begin after age 50

  • Worsening vision

  • Weight loss

  • Headaches that are getting worse or more frequent

If you are older than 50 years old, any new headache or change in old headache should be seen by a doctor. Older people are more likely to have a serious cause for a headache, and even common headaches may be more difficult to treat in older people.

What will happen at my doctor visit?

Your doctor will ask you questions about your symptoms and examine you. Your doctor may also do tests such as:

How do doctors treat headaches?

Treatment depends on the type of headache you have:

  • If another health problem is causing your headache, doctors will treat that problem

  • For tension headaches or headaches due to viruses, doctors will have you take pain medicine such as aspirin, acetaminophen, or ibuprofen

  • For migraine, doctors will give you special medicine

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NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
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