Health Insights · Neurology
Headache: common causes and warning signs
Almost everyone gets headaches, and the great majority are tension-type or migraine. A small number signal something needing urgent attention, and they are identified by specific features rather than by severity — a very painful headache is usually a migraine, while a dangerous one can be moderate.
Call 999 if a headache is
- sudden and severe, peaking within seconds to a minute — thunderclap headache
- with neck stiffness, fever or a rash that does not fade
- with weakness, numbness, visual loss or difficulty speaking
- with confusion, drowsiness or a seizure
- after a head injury, particularly if you take anticoagulants
- with a red painful eye and blurred vision or haloes
A thunderclap headache reaching maximum intensity within a minute may be a subarachnoid haemorrhage and needs immediate assessment even if it settles. Headache with fever and neck stiffness may be meningitis. In an emergency call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
Other features needing prompt assessment
- a new headache over the age of 50, particularly with scalp tenderness or jaw ache on chewing — possible giant cell arteritis, which can cause sudden blindness
- headache worse on lying down, coughing, straining or bending
- headache that wakes you from sleep, or is worst first thing and improves through the day
- a headache that has changed in character from your usual pattern
- headache with weight loss, fever or night sweats
- headache in someone immunosuppressed or with a history of cancer
- headache in pregnancy or just after birth, with visual change or swelling
The common types
- Tension-type — a band of pressure around the head, both sides, mild to moderate, not worsened by activity, without nausea. The commonest by far.
- Migraine — usually one-sided, throbbing, moderate to severe, lasting 4 to 72 hours, worsened by movement, with nausea and dislike of light or sound. Sometimes preceded by aura.
- Cluster headache — excruciating pain around one eye, lasting 15 minutes to 3 hours, occurring daily in bouts over weeks, with a red watering eye, drooping lid and blocked nostril on that side. People are restless and pace rather than lying still.
- Sinus headache — genuinely uncommon, and frequently a misdiagnosed migraine. Real sinusitis has nasal blockage and discoloured discharge.
- Cervicogenic — arising from the neck, often one-sided, with restricted neck movement.
Medication overuse headache
Taking painkillers for headache on 10 or more days a month for simple analgesics, or 15 or more for triptans, codeine or combination painkillers, causes the very headaches you are treating. It creeps up over months and produces a near-daily background headache. The only treatment is stopping the painkillers, which causes a worse headache for one to two weeks before it improves substantially. This is extremely common, rarely recognised, and entirely reversible — but it needs planning and support rather than willpower alone.
Cluster headache is not migraine
It is often misdiagnosed for years, and the treatments are different: high-flow oxygen and injectable or nasal triptans for attacks, and verapamil for prevention. Ordinary painkillers do nothing — attacks are over before tablets are absorbed. If you have strictly one-sided attacks around the eye with tearing and a blocked nose, lasting under three hours and coming in daily bouts, say so specifically.
Do you need a scan?
For most headaches, no. Imaging is not recommended for typical migraine or tension-type headache with a normal examination, because the yield is very low and incidental findings cause harm. Scans are indicated where red flags are present, the examination is abnormal, the pattern has changed, or there is a specific concern — and in those situations they should be arranged promptly.
Keeping a diary
Two months of a simple headache diary — date, duration, severity, features, what you took and how many days a month — is more useful than any test for headaches without red flags. It identifies the type, reveals medication overuse, and shows triggers. Bring it to your appointment.
Why come to us. Most headaches need a careful history, an examination and reassurance rather than a scan — but the ones that do need acting on need it quickly. We offer unhurried appointments, examine you properly including your eyes and blood pressure, take inflammatory markers and bloods in-house where giant cell arteritis or another cause is in question, and arrange MRI or CT through our CQC-registered partners without a wait where imaging is genuinely indicated. 7 days a week.
Private assessment for headaches in East London
Most headaches are tension-type or migraine and settle with the right approach, but certain patterns need urgent attention. A private GP in East London can assess you and arrange imaging where warranted, involving our specialist medicine team for ongoing or complex headaches. A sudden 'worst-ever' headache, or headache with fever and a stiff neck, weakness, or confusion, needs emergency care — call 999. Tower Bridge Hospital is on Whitechapel Road in East London, a short journey from Canary Wharf and the City, with same-day appointments and no referral required.
Headache in London: common questions
When is a headache a red flag?
A sudden severe 'thunderclap' headache, headache with fever and neck stiffness, new weakness or confusion, or one that steadily worsens — seek emergency care.
What causes most headaches?
Tension-type headache and migraine are the commonest; medication-overuse and lifestyle factors often contribute.
Do I need a brain scan?
Most headaches do not need a scan; imaging is arranged where the pattern or examination raises concern.
Can I be seen the same day?
Yes — same-day private GP appointments are available most days.
Assessed properly, scanned only when it is warranted
Bloods in-house, imaging arranged fast. 7 days a week.