Dangerous headache warning signs
The vast majority of headaches are primary headaches — benign, though often debilitating. A small but important minority are secondary headaches caused by an underlying condition, some of which are life-threatening. Recognising red flags is essential.
Thunderclap: Sudden, severe headache reaching maximum intensity within 60 seconds — "worst headache of my life" · With fever + stiff neck: possible meningitis · With neurological symptoms: weakness, speech difficulty, vision loss, confusion, face drooping · After head trauma · In a known cancer or immunocompromised patient · Progressive over days/weeks (not episodic) · Waking from sleep with severe pain · New headache in anyone over 50
Systemic symptoms (fever, weight loss) · Neurological symptoms · Onset sudden (thunderclap) · Older age (new headache over 50) · Progressive pattern · Precipitated by Valsalva (coughing, sneezing, straining) · Postural component (much worse lying down or standing) · Papilloedema (swelling around optic nerve)
Tension-type headache
Tension-type headache (TTH) is the most common headache disorder — affecting up to 78% of the general population at some point. Despite its prevalence, it remains poorly understood and frequently undertreated.
Characteristics
| Feature | Tension-type headache |
|---|---|
| Location | Bilateral — "band around the head" or vice-like pressure; forehead, temples, or back of head |
| Quality | Pressing or tightening; dull, aching — never throbbing |
| Severity | Mild to moderate — does not prevent activity |
| Duration | 30 minutes to 7 days |
| Nausea | Absent or mild nausea only — no vomiting |
| Light/sound sensitivity | One or the other may be present, but not both (unlike migraine) |
| Activity effect | Not worsened by routine physical activity |
| Frequency | Episodic (<15 days/month) or chronic (≥15 days/month for >3 months) |
Causes and treatment
The exact mechanism is debated — peripheral sensitisation of pericranial muscles and central pain sensitisation both play roles. Common triggers include stress, poor posture, eye strain, jaw clenching (bruxism), dehydration, and sleep deprivation.
Treatment for episodic TTH: simple analgesics (paracetamol/acetaminophen, ibuprofen, aspirin) taken early. Combination products (paracetamol + caffeine + aspirin) are more effective but risk medication overuse headache if used more than 10–15 days per month. For chronic TTH, amitriptyline (10–75 mg at night) is the most evidence-based preventive treatment. Physiotherapy targeting neck and shoulder muscles, biofeedback, and CBT also have good evidence.
Using pain medication (analgesics, triptans, opioids) for headache on 10 or more days per month can paradoxically cause chronic daily headache — medication overuse headache. If you find yourself using headache medication more than twice a week, speak to your doctor about preventive therapy. Withdrawal and preventive treatment break the cycle but require medical guidance.
Migraine
Migraine is a complex neurological disorder affecting 1 billion people worldwide — approximately 12% of the global population. It is the second leading cause of disability globally and the most disabling neurological condition. Despite this, it remains significantly underdiagnosed and undertreated, particularly in women.
Migraine is not "just a bad headache." It involves complex neurobiological changes including cortical spreading depression, trigeminal nerve activation, neurogenic inflammation, and central sensitisation. The pain is typically severe and often incapacitating.
The four phases of migraine
1️⃣ Prodrome
- Hours to days before headache
- Mood changes (depression or euphoria)
- Food cravings
- Yawning, fatigue
- Neck stiffness
- Increased urination
2️⃣ Aura (25% of migraineurs)
- 20–60 minutes before headache
- Visual: zigzag lines, blind spots, flashing lights
- Sensory: tingling face or hand
- Speech: word-finding difficulty
- Motor (rare): hemiplegic migraine
- Fully reversible within 60 minutes
3️⃣ Headache phase
- 4–72 hours untreated
- Unilateral in 60% (but can be bilateral)
- Pulsating/throbbing
- Moderate to severe
- Nausea or vomiting
- Photo- and phonophobia
4️⃣ Postdrome
- Up to 48 hours after pain
- "Migraine hangover"
- Fatigue, cognitive fog
- Mood changes
- Scalp tenderness
- Often underrecognised
Migraine treatments
Acute treatment works best when taken early in the attack — ideally at the first sign of headache (not during aura, as vasoconstriction risk). Lying down in a dark, quiet room and applying cold compresses to the forehead or back of neck can supplement medication.
| Drug | Class | Efficacy | Notes |
|---|---|---|---|
| Triptans (sumatriptan, rizatriptan, zolmitriptan) | 5-HT1B/1D agonists — migraine-specific | 60–70% pain freedom at 2 hours | First-line for moderate-severe migraine; available oral, nasal, and injectable; avoid in cardiovascular disease, hemiplegic migraine, basilar migraine |
| Gepants (ubrogepant, rimegepant) | CGRP receptor antagonists — oral, acute | 20–25% pain freedom at 2 hours | No vasoconstriction — safe in cardiovascular disease; rimegepant also licensed for prevention; can be used with triptans |
| Lasmiditan (Reyvow) | 5-HT1F agonist ("ditan") | 28–40% pain freedom at 2 hours | No vasoconstriction; safe in CV disease; drowsiness; do not drive for 8 hours |
| NSAIDs (ibuprofen 400–600 mg, naproxen 550 mg, aspirin 900 mg) | COX inhibitors | Moderate — better for mild-moderate attacks | Take early; combine with metoclopramide to improve absorption; effective and inexpensive first-line |
| Metoclopramide / prochlorperazine | Dopamine antagonists — anti-emetic | Moderate — adjunct and standalone | Also treat nausea; prochlorperazine (Compazine/Stemetil) has direct anti-migraine effect; useful when oral medication is limited by vomiting |
| Dihydroergotamine (DHE) | Ergot alkaloid | High — especially for status migrainosus | Nasal spray or injectable; used in ER for refractory attacks; contraindicated with triptans (24-hour gap) |
Preventive treatment is indicated when migraine occurs 4+ days per month, causes significant disability, or does not respond adequately to acute treatment. The goal is to reduce attack frequency, severity, and duration — not to eliminate all attacks.
| Drug | Migraine frequency reduction | Best suited for | Key considerations |
|---|---|---|---|
| Topiramate (Topamax) | ~50% reduction in ~50% of patients | First-line; also benefits weight | Cognitive side effects ("dopamax"); teratogenic; kidney stones; titrate slowly |
| Propranolol / metoprolol | ~50% reduction | First-line; especially with anxiety or hypertension | Avoid in asthma, depression, peripheral artery disease; bradycardia |
| Amitriptyline | ~40–50% reduction | Comorbid depression, insomnia, or TTH | Low dose (10–75 mg); sedation; weight gain; avoid in cardiac arrhythmias |
| Valproate (valproic acid) | ~50% reduction | Especially with epilepsy comorbidity | Highly teratogenic — avoid in women of childbearing age; weight gain; liver monitoring |
| Candesartan | ~40% reduction | Good tolerability; hypertension comorbidity | ARB class; less studied than beta-blockers but excellent tolerability |
| OnabotulinumtoxinA (Botox) | ~30–50% reduction | Chronic migraine (≥15 days/month) | 31 injections across scalp/neck every 12 weeks; NHS/insurance approved for chronic migraine; highly effective |
| Magnesium | ~40% reduction (some trials) | Menstrual migraine; well-tolerated supplement | 400–600 mg magnesium oxide or citrate daily; GI side effects; safe in pregnancy |
| Riboflavin (B2) | ~50% reduction in open trials | Well-tolerated; evidence modest | 400 mg daily; yellow urine; mitochondrial mechanism |
CGRP (calcitonin gene-related peptide) is a neuropeptide released during migraine attacks that causes vasodilation and neurogenic inflammation. CGRP therapies have revolutionised migraine prevention — offering targeted, well-tolerated monthly or quarterly injections with no CNS side effects.
| Drug | Target | Dosing | Efficacy |
|---|---|---|---|
| Erenumab (Aimovig) | Anti-CGRP receptor | Monthly SC injection; self-administered | ~50% reduction in ~50% of patients; some achieve complete response |
| Fremanezumab (Ajovy) | Anti-CGRP ligand | Monthly or quarterly SC injection | Similar efficacy; quarterly dosing preferred by many patients |
| Galcanezumab (Emgality) | Anti-CGRP ligand | Monthly SC injection; loading dose | Also approved for cluster headache — only preventive approved for this indication |
| Eptinezumab (Vyepti) | Anti-CGRP ligand | Quarterly IV infusion | Rapid onset — benefit from day 1; useful for frequent or status migrainosus |
| Rimegepant (Nurtec) | CGRP receptor antagonist (oral) | Every other day oral — acute and preventive | Dual acute/preventive use; no rebound headache; cardiovascular safe |
| Atogepant (Qulipta) | CGRP receptor antagonist (oral) | Daily oral preventive | ~60% achieve ≥50% reduction; no vasoconstriction; liver enzyme monitoring |
CGRP monoclonal antibodies are generally considered after two or more oral preventives have failed. They are now available in many countries and increasingly covered by insurance/NHS for episodic migraine (4+ days/month) and chronic migraine (15+ days/month).
Cluster headache
Cluster headache is one of the most painful conditions known to medicine — sometimes called "suicide headache" because of the extreme pain. It is rare (affecting ~0.1% of the population) but severely disabling during cluster periods.
| Feature | Description |
|---|---|
| Pain character | Excruciating, boring, burning, or piercing — described as "a hot poker through the eye"; strictly unilateral, always same side within a cluster |
| Location | Around, behind, or through one eye; temple; face |
| Duration | 15–180 minutes per attack |
| Frequency | 1–8 attacks per day, often at the same time (particularly at night — "alarm clock headache") |
| Cluster period | Weeks to months of daily attacks, followed by remission lasting months to years (episodic form); chronic form: no remission >3 months |
| Autonomic features | Ipsilateral (same side): tearing, red eye, drooping eyelid (ptosis), nasal congestion or runny nose, facial sweating, miosis — absent in migraine |
| Behaviour during attack | Typically agitated, pacing, rocking — cannot lie still (opposite to migraine, where patients lie still in the dark) |
| Sex | Male predominance (3:1); previously thought to be almost exclusively male, but increasing recognition in women |
Cluster headache treatment
- Acute attack — 100% oxygen: High-flow oxygen (12–15 L/min via non-rebreather mask for 15–20 minutes) aborts attacks in ~70% of patients within minutes. The most effective and safest acute treatment — underused because patients often don't know about it.
- Acute attack — subcutaneous sumatriptan (6 mg): Fastest-acting triptan formulation; aborts attack in ~74% within 15 minutes.
- Acute attack — zolmitriptan nasal spray: Alternative when injection is not preferred.
- Prevention — verapamil: First-line preventive; 240–960 mg/day; ECG monitoring required at high doses (PR interval prolongation).
- Prevention — galcanezumab: The only CGRP antibody approved for episodic cluster headache; three monthly loading doses; not effective for chronic cluster.
- Prevention — short-course prednisolone: Used as a bridge while verapamil is being titrated; rapid onset but cannot be used long-term.
- Neuromodulation: Non-invasive vagus nerve stimulation (nVNS; gammaCore) approved for both acute and preventive cluster treatment; sphenopalatine ganglion (SPG) stimulation for chronic cluster.
Secondary headaches: important causes
| Cause | Key features | Action |
|---|---|---|
| Subarachnoid haemorrhage | Thunderclap — "worst headache of my life"; may have brief loss of consciousness; neck stiffness; photophobia | 911 immediately |
| Meningitis / encephalitis | Headache + fever + neck stiffness + photophobia; rash (meningococcal); altered consciousness | 911 immediately |
| Hypertensive crisis | Severe headache with BP ≥180/120; may have visual changes, confusion, chest pain | 911 immediately |
| Cerebral venous sinus thrombosis | Progressive headache; OCP use; pregnancy/postpartum; papilloedema; focal neurology | Emergency |
| Brain tumour | Progressive headache; worse lying down or Valsalva; morning vomiting; focal neurology; personality change | Urgent neurology |
| Giant cell arteritis (GCA) | New headache in age 50+; scalp tenderness; jaw claudication; visual loss risk; elevated ESR/CRP | Same-day evaluation |
| Idiopathic intracranial hypertension | Obese woman; pulsatile tinnitus; visual obscurations; papilloedema; worsens lying flat | Urgent neurology |
| Post-concussion headache | Follows head injury; may last weeks to months; cognitive symptoms; light/noise sensitivity | Medical evaluation |
| Sinusitis | Facial pressure/pain; nasal congestion; purulent discharge; worse bending forward | Primary care |
Common headache triggers
- Stress and stress let-down: "Weekend migraines" occur as stress hormones fall after a demanding week — keep weekend schedules as consistent as weekday ones.
- Sleep disruption: Both too little and too much sleep trigger attacks. Maintain consistent sleep and wake times, including weekends.
- Dehydration: Even mild dehydration triggers headache. Aim for 2–3 litres of water daily; more in heat or exercise.
- Skipping meals: Hypoglycaemia is a potent migraine trigger. Eat regular meals; carry a snack.
- Hormonal changes: Oestrogen drops around menstruation trigger perimenstrual migraine in many women. Continuous hormonal contraception or mini-pill can stabilise oestrogen.
- Alcohol: Red wine (tyramine, histamine), beer, and spirits all trigger migraines in susceptible individuals. Even small amounts can trigger attacks in some people.
- Caffeine: Moderate caffeine can relieve headache; caffeine withdrawal (missing your morning coffee) reliably triggers one. Gradual reduction avoids withdrawal headache.
- Sensory overload: Bright lights, flickering screens, strong smells, loud noise — reduce or manage with dark glasses, earplugs, or fragrance-free environments during vulnerable periods.
- Weather changes: Barometric pressure changes reliably trigger migraines in many sufferers. Weather apps that show pressure trends can help anticipate and pre-treat attacks.
Non-pharmacological approaches
- Headache diary: Tracking headache days, potential triggers, menstrual cycle, sleep, and medication use for 2–3 months reveals patterns and informs both trigger avoidance and treatment decisions. Apps like Migraine Buddy or N1-Headache are well-validated.
- Biofeedback: Teaches physiological self-regulation (muscle tension, skin temperature, heart rate variability) — evidence-based for migraine and tension-type headache; comparable to propranolol in some studies.
- Cognitive Behavioural Therapy (CBT): Addresses catastrophising, disability behaviour, and activity avoidance that amplify headache burden.
- Acupuncture: Multiple high-quality trials show acupuncture is at least as effective as prophylactic drug treatment for migraine. NICE recommends up to 10 sessions for chronic migraine or TTH.
- Mindfulness-Based Stress Reduction (MBSR): Reduces headache frequency and improves headache-related disability in chronic migraine.
- Neuromodulation devices: External trigeminal nerve stimulation (Cefaly), remote electrical neuromodulation (Nerivio), gammaCore vagal nerve stimulator — approved, well-tolerated, no systemic side effects.
Frequently asked questions
A thunderclap headache — sudden, severe pain reaching maximum intensity within 60 seconds, often described as "the worst headache of my life" — is a medical emergency until proven otherwise. The most serious cause is subarachnoid haemorrhage from a ruptured brain aneurysm, which is fatal in up to 45% of cases. Other serious causes include cerebral venous sinus thrombosis, hypertensive crisis, and reversible cerebral vasoconstriction syndrome. Call 911 immediately — do not wait to see if it improves.
Common migraine triggers include hormonal changes (oestrogen fluctuations around menstruation), stress and stress let-down ("weekend migraines"), irregular sleep, skipping meals, dehydration, certain foods (aged cheeses, processed meats, alcohol — especially red wine), strong sensory stimuli, weather changes, and caffeine withdrawal. Triggers are highly individual — keeping a headache diary for 2–3 months to identify your personal triggers is one of the most effective management strategies available.
Migraine is a neurological disorder — not simply a severe headache. It involves complex brain chemistry changes producing severe, typically one-sided throbbing pain lasting 4–72 hours, accompanied by nausea, vomiting, and extreme sensitivity to light, sound, and smell. About 25% of migraineurs experience aura — neurological symptoms preceding the headache. Tension-type headaches, by contrast, are bilateral, pressing or tightening in quality, mild to moderate in severity, and not associated with nausea or light sensitivity. The distinction matters enormously for treatment — triptans are highly effective for migraine but not for tension headache.
- Headache Classification Committee of the International Headache Society (IHS). ICHD-3: The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38(1):1–211.
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- Marmura MJ, et al. The Acute Treatment of Migraine in Adults: The American Headache Society Evidence Assessment of Migraine Pharmacotherapies. Headache. 2015;55(1):3–20.
- Silberstein SD, et al. Evidence-Based Guideline Update: Pharmacologic Treatment for Episodic Migraine Prevention in Adults. Neurology. 2012;78(17):1337–1345.
- Goadsby PJ, et al. A Controlled Trial of Erenumab for Episodic Migraine. NEJM. 2017;377:2123–2132.
- Linde K, et al. Acupuncture for the prevention of episodic migraine. Cochrane Database Syst Rev. 2016;6:CD001218.