Acute headache assessment (Diagnostic assessment of acute (new or sudden) headache)

What is an acute headache assessment?

An acute headache assessment is how a doctor decides whether a new or changed headache is a harmless type (such as migraine or tension headache) or a sign of something serious that needs urgent treatment. Most headaches are not dangerous, but a small number signal conditions like bleeding around the brain, meningitis or raised pressure in the head.

The assessment starts with detailed questions and an examination, looking for 'red flags' — features that raise concern. Depending on what is found, the doctor may arrange tests such as a CT brain scan, a lumbar puncture (a sample of the fluid around the spinal cord), blood tests, or an MRI scan. Many people need no scan at all once a careful assessment is done.

The purpose is not to scan every headache, but to safely separate the few serious causes from the many that are not, and to set up the right treatment or reassurance.

Some headache patterns are emergencies. A sudden 'thunderclap' headache that reaches its worst within minutes, or the worst headache of your life, can mean bleeding around the brain. A headache with fever, a stiff neck, a rash, drowsiness or confusion can mean meningitis. These need 999 or A&E now — not a private booking.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Options at a glance

These are the main approaches described in this guide. The right option depends on the diagnosis, your goals and what your clinician thinks is safe.

Preparing for your test

• If the headache was sudden and severe, came on like a thunderclap, or comes with fever, stiff neck, rash, drowsiness, confusion or weakness, do not prepare — call 999 or go to A&E now.
• Be ready to describe exactly how the headache started and how quickly it reached its worst — this is one of the most important clues.
• Bring a list of your medicines, including painkillers and how often you take them, and any recent new medicines.
• Note any recent head injury, pregnancy, recent childbirth, or a weakened immune system.
• Mention previous headaches and whether this one is different from your usual pattern.
• Bring your glasses if you wear them, as part of the examination looks at your eyes.

What happens

A doctor asks in detail about the headache — especially how suddenly it began, how fast it peaked, and any associated symptoms — and about your medical history and medicines. They examine you, including a neurological examination and a look at the back of your eyes.

If the assessment is reassuring and there are no red flags, you may need no scan and can be given a diagnosis, treatment and safety advice. If there are red flags, the doctor arranges tests. For a sudden severe headache, this usually means an urgent CT brain scan, sometimes followed by a lumbar puncture if the CT is normal but bleeding or infection is still possible.

Depending on the results, you may be reassured and discharged with a plan, started on treatment, kept in for observation, or referred urgently to a specialist such as a neurologist or neurosurgeon.

Is this test right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

The central risk is missing a rare but dangerous cause, which is why sudden, severe or 'red-flag' headaches must be assessed urgently and not through a routine private booking. The opposite risk is over-scanning ordinary headaches, exposing people to radiation, incidental findings and anxiety. Ask which red flags you do or do not have, what each test would change, and what a normal result does and does not rule out.

Published figures to discuss

Useful single percentages are limited because the chance of a serious cause depends heavily on the exact symptoms, and test accuracy depends on timing and technique. The figures below are illustrative and should be discussed with your doctor, not applied to yourself directly.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

There is usually no physical recovery from the assessment itself. What matters afterwards is the diagnosis, any treatment, and clear advice on what would mean coming back urgently.

• Tiredness and emotional strain after an urgent assessment
• A mild bruise where blood was taken or a drip was placed
• A headache for a few days after a lumbar puncture in some people
• Gradual improvement once any treatment for the diagnosed cause starts

Aftercare

• Follow the treatment plan for the diagnosed cause, whether that is migraine, tension headache or something else.
• If you had a lumbar puncture, follow the advice given about fluids, rest and what to do if a headache develops.
• Keep a headache diary if asked, noting triggers, frequency and painkiller use.
• Avoid taking painkillers too often, as overuse can itself cause headaches — ask for advice on limits.
• Attend any follow-up or specialist appointment arranged for you.
• Return urgently if the headache changes character, becomes the worst ever, or new symptoms appear.
• Make sure you understand what a normal result did and did not rule out.

• A clear description ready of how the headache started and peaked
• An up-to-date list of medicines, including painkiller frequency
• Note of any recent head injury, pregnancy or immune problems
• Someone to be with you, especially if you feel unwell
• A written copy of your diagnosis and plan
• The contact number for questions or worsening symptoms
• A clear list of warning signs that mean returning urgently

Scars and how they heal

There are no surgical wounds. You may have a small bruise where blood is taken or a drip is placed. A lumbar puncture leaves a tiny puncture mark in the lower back that heals quickly.

⚠ Get urgent help if…

• A sudden, severe headache that reaches its worst within minutes ('thunderclap') or the worst headache of your life — call 999
• Headache with fever, a stiff neck, a rash, or dislike of bright light — call 999 (possible meningitis)
• Headache with drowsiness, confusion, fits, weakness, numbness or difficulty speaking — call 999
• Headache after a head injury, especially with vomiting or drowsiness — seek urgent help
• A new headache with jaw pain on chewing, scalp tenderness or visual loss in an older person — seek urgent help (possible giant cell arteritis)
• A headache that is steadily worsening over days or wakes you from sleep — seek urgent medical advice

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

A reassuring assessment with no red flags, or normal tests where they were needed, usually points to a non-dangerous headache such as migraine or tension type, which can be treated. A test that shows bleeding, infection or another serious cause leads to urgent treatment or referral.

A normal CT scan is reassuring but does not rule out every cause, which is why a lumbar puncture or further imaging is sometimes still needed. Results should always be explained alongside your symptoms and examination, not in isolation.

The assessment relates to this episode. It does not prevent future headaches. If you have a recognised headache disorder such as migraine, the plan may need reviewing as your pattern changes. A new or different headache in future should be assessed again rather than assumed to be the same as before.

Related tests, treatments or support

The assessment often combines history and examination with blood tests, and a CT scan with a lumbar puncture when a sudden severe headache needs to exclude bleeding or infection. MRI and vessel imaging may be added when the first tests are normal but concern remains.

Follow-up & long-term care

If a benign headache is diagnosed, follow-up is usually with your GP or a headache specialist for ongoing management. If a serious cause is found or suspected, you will be referred urgently. Either way, you should leave with clear advice on warning signs and when to return.

• For recognised headache disorders, keep a diary and review treatment as the pattern changes
• Watch painkiller frequency to avoid medication-overuse headache
• Know which new symptoms mean a fresh urgent assessment is needed

Repeat, follow-on and what comes next

• A normal CT may need to be followed by a lumbar puncture or MRI when concern remains.
• A first diagnosis of a primary headache may be revised if the pattern changes or treatment fails.
• Incidental findings on imaging can lead to further tests that turn out to be unnecessary.
• A new, different headache in future should prompt a fresh assessment rather than assuming the old diagnosis.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• A named contact and explicit safety-netting on warning signs and when to call 999.
• A written diagnosis and treatment plan, with advice on painkiller limits.
• Clear explanation of what any normal result did and did not rule out.
• Onward referral to neurology or another specialist when appropriate.
• Joined-up handover to the GP for ongoing headache management.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• The length and complexity of the consultation and examination
• Whether a scan is needed, and which type (CT, MRI, or vessel imaging)
• Whether a lumbar puncture or blood tests are required
• The reporting radiologist and how quickly results are needed
• Whether specialist (neurology) input is included
• Follow-up appointments and any ongoing treatment plan

• The assessing clinician's fee and the length of appointment
• Any scan fee and the radiologist's reporting fee
• Blood tests, lumbar puncture or other investigations if needed
• What happens, and what it costs, if results are abnormal or inconclusive
• Onward referral to a specialist if required
• Follow-up and review of any ongoing headache treatment
• A clear statement that emergency features will be redirected to NHS emergency care

On the NHS? Assessment of a sudden, severe or worrying new headache is emergency NHS care via A&E and acute medicine. Private same-day medicine may help investigate stable, recurrent or lower-risk headaches quickly, but it must never replace emergency care when serious features are present.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• Which red flags do I have or not have, and what do they mean for me?
• Do I need a scan or a lumbar puncture, and what will the result change?
• What does a normal scan rule out, and what does it not rule out?
• What is the most likely cause of my headache and how is it treated?
• How often is it safe to take painkillers without causing more headaches?
• What new symptoms should make me come back urgently?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my test, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this test not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for acute headache assessment

Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.

How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NHS — Subarachnoid haemorrhage NHS — Brain aneurysm NHS Scotland — National headache pathway (Right Decisions) SNNOOP10: red and orange flags for secondary headaches (PMC) Sudden onset severe headache in the ED: systematic review of diagnostic accuracy (PMC) Secondary headache in the emergency department (PMC)

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.