Last reviewed: October 2026 · ← All health guides

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Warning signs: when a headache needs a doctor

Most headaches are harmless. Brain tumours cause only a very small share of them. But a headache with any sign below needs a doctor, and the doctor should consider whether a brain scan is needed.

See a doctor within days if:

1. A new headache starts after age 50.
2. The headache keeps coming back for more than 4 to 6 weeks, or gets steadily worse.
3. The pattern changes: stronger, more often, or different from your usual headaches.
4. It wakes you from sleep, or is worst on waking in the morning.
5. It gets worse when you cough, sneeze, bend or strain.
6. Treatment, including migraine medicine, stops working or never worked.
7. You have a history of cancer, a weak immune system, or a past brain injury or bleed.

The key word is change. A familiar headache that behaves the same way for years is usually benign. A headache that is new, changing or not responding to treatment needs a doctor’s review.

Why this guide exists

The lessons

1. Migraine is usually diagnosed from symptoms. Without a scan, it is a working diagnosis.
2. If a headache keeps coming back for months, changes, or does not respond to treatment, ask your doctor whether a scan is needed.
3. You can ask your doctor: “Have we ruled out anything serious?” and “Why is a scan not needed?”
4. If you are still unsure, a second opinion from a neurologist is reasonable.

Why a headache keeps coming back

Most persistent headaches have a common, treatable cause. A few have a serious one. Telling them apart is the doctor’s job.

If the common causes have been looked at and treated and the headache still persists, your doctor may consider a scan as the next step.

Brain tumour signs besides headache

A headache alone is rarely a tumour. A headache together with any of these needs a doctor soon.

• A first fit (seizure) in an adult
• Gradual weakness, numbness or clumsiness in an arm or leg
• Changes in speech, understanding or finding words
• Changes in vision: blurring, double vision, loss of part of the visual field
• Personality or behaviour change, confusion, memory loss
• Loss of balance or coordination
• Nausea or vomiting with no stomach cause, especially in the morning
• Unusual drowsiness
• Hearing loss in one ear, or ringing in one ear

Family and colleagues often notice personality or memory changes before the patient does. Tell the doctor about them.

CT or MRI, and the downsides of scanning too often

The right scan at the right time can help a great deal. Scanning without a reason, or too often, has real costs. The aim is one well-chosen scan when warning signs are present, not routine repeat scans. Your doctor decides which scan is right for you.

Disadvantages of frequent scans

1. Radiation from CT adds up. Each CT adds a very small cancer risk over a lifetime. The risk is higher in children and young adults. Avoid repeat CTs without a clear reason, and keep a record of every scan you have had.
2. Contrast dye can harm the kidneys and can cause allergic reactions. Tell the doctor your creatinine, any allergy, and whether you have diabetes before any contrast scan.
3. Gadolinium (MRI dye) is risky in severe kidney disease, and small amounts can stay in the body after repeated doses. It should be used only when the doctor needs it.
4. Incidental findings. Scans often show small harmless spots. These cause worry, more tests, and sometimes unneeded procedures.
5. False reassurance. A normal scan does not mean the headache can be ignored if it later changes. A new pattern needs a new review.
6. MRI is not safe for everyone. It cannot be done with some pacemakers, cochlear implants or metal fragments. It can be hard for people who fear closed spaces.
7. Pregnancy. Avoid CT and contrast dye unless essential; tell the staff if you may be pregnant.
8. Cost and time, especially for repeated scans that do not change treatment.

What to do if your headache keeps coming back

Keep a headache diary for 2 to 4 weeks

1. Date, time it started, and how long it lasted.
2. Pain level from 1 to 10, and where it hurts.
3. What you were doing, eating or drinking before it.
4. Sleep the night before.
5. Medicines taken and whether they helped.
6. Any other symptom: vomiting, vision change, weakness, numbness.
7. BP reading during the headache, if you can check it.

Questions to ask the doctor

1. What do you think is causing my headache?
2. Have we ruled out anything serious? How?
3. Do I need a brain scan? If not, why not?
4. What change in my headache should make me come back sooner?
5. If this treatment does not work in 4 to 6 weeks, what is the next step?
6. Should I see a neurologist?

Avoid

• Taking painkillers on more than 10 to 15 days a month without a doctor’s plan
• Changing doctors repeatedly without carrying your old reports
• Carrying on for months with a headache that is not improving, without going back to ask questions

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