Health information to help you understand symptoms. It isn't a diagnosis.
Check symptoms

Headache on one side of the head

Also called: One-sided headache, unilateral headache, migraine

A headache on one side of the head is most often a migraine. Cluster headaches cause severe pain around one eye. Less often, one-sided headaches come from nerve problems, sinus infections, or, rarely, serious problems like a stroke or bleeding in the brain. A sudden, severe one-sided headache needs 911.

Common causesMigraine, cluster headache, sinus problems, nerve pain
Usually serious?Usually not
Get checked ifIt's sudden and severe, or has nerve symptoms
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

Migraines are often throbbing pain on one side of the head that lasts 4 to 72 hours, with nausea, vomiting, and sensitivity to light and sound. Some people see flashing lights or zigzag lines (an aura) before the headache.

Cluster headaches are very severe, stabbing pain around one eye with tearing and a stuffy nose on the same side. Occipital neuralgia causes shooting pain from the base of the skull. A headache always on the same side that's getting worse should be checked.

When to get medical care

Call 911Sudden, severe 'worst headache of your life.' Headache with weakness, numbness, trouble speaking, vision loss, or confusion. Headache with fever and a stiff neck. Headache after a head injury. A headache with a droopy eyelid and a large pupil on the same side.
Get care todayYour first severe headache, especially after age 50. A headache that's different from your usual headaches. A headache with fever, or that's worse when lying down.
See a doctor soonHeadaches that keep coming back. Headaches always on the same side. Headaches that are getting more frequent or severe. Needing pain medicine more than 2 or 3 days a week.

Causes

Common causes include migraine, cluster headache, tension headache, sinus infection, and dental problems. Other causes include occipital neuralgia, trigeminal neuralgia, giant cell arteritis, eye problems like acute glaucoma, and, rarely, stroke, bleeding in the brain, aneurysm, or a brain tumor.

OwieClear has pages on 2 conditions that can cause headache on one side of the head. Each shows how soon to get care.

Common causes

  • MigraineSee a doctor if it doesn't get better

    A headache that often throbs on one side and may come with nausea or light sensitivity.

  • Cluster headacheSee a doctor if it doesn't get better

    Very severe pain in or around one eye or temple, often with a watery eye or runny nose on the same side.

What you can do at home

  • Rest in a quiet, dark room at the first sign of a migraine.
  • Put a cold pack on your forehead or neck.
  • Drink water and eat regular meals.
  • Keep a headache diary to find triggers like certain foods, sleep changes, or stress.
  • Keep a regular sleep schedule.

Medicines

Ibuprofen, naproxen, or acetaminophen taken early can help migraines. Prescription triptans and other medicines can stop migraines, and preventive medicines can reduce how often they happen. Limit pain relievers to 2 or 3 days a week to avoid rebound headaches.

At the doctor

The provider will find the headache type from your symptoms and exam.

Questions you may be asked

  • Where the pain is and what it feels like
  • How long it lasts and how often
  • Nausea, light sensitivity, or aura
  • Eye tearing or a stuffy nose
  • Triggers and family history

The exam

A physical and nerve exam.

Tests

  • Usually no tests
  • An MRI or CT if there are warning signs or a change in pattern

Prevention

You can reduce migraines.

  • Avoid your triggers
  • Keep regular sleep and meals
  • Exercise regularly
  • Ask about preventive medicine

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

Start the symptom checker

Sources

Last updated 2026-11-13.