Headache and Pain: Red Flags Before Reassurance
Screen for secondary causes first
Headache items reward pattern recognition, but only after secondary causes are excluded. Memorize red flags: sudden thunderclap onset, new headache after age 50, systemic symptoms such as fever or weight loss, neurologic deficit, papilledema, positional provocation, pregnancy or puerperium, and progressive course.
Migraine. Diagnostic criteria require at least five attacks lasting 4 to 72 hours with two of four features (unilateral, pulsating, moderate to severe, worsened by activity) plus one of nausea/vomiting or photophobia and phonophobia. Chronic migraine means 15 or more headache days monthly for over three months with at least eight migraine days. Medication overuse headache should be assessed in every high-frequency patient. Preventive options include topiramate, propranolol, amitriptyline, candesartan, CGRP monoclonal antibodies, and gepants. Triptans are contraindicated with coronary disease, uncontrolled hypertension, and certain vascular conditions.
Cluster headache. Severe unilateral orbital or temporal pain lasting 15 to 180 minutes with ipsilateral autonomic features (lacrimation, rhinorrhea, ptosis, miosis) and restlessness. Acute treatment is high-flow oxygen or subcutaneous sumatriptan; verapamil is preventive and requires ECG monitoring.
Other distinctive syndromes. Paroxysmal hemicrania responds absolutely to indomethacin. SUNCT/SUNA involves very brief neuralgiform attacks. Idiopathic intracranial hypertension produces pressure-type headache, transient visual obscurations, pulsatile tinnitus, and papilledema, mostly in women with elevated body mass index. Postural headache suggests intracranial hypotension; giant cell arteritis suggests scalp tenderness and elevated inflammatory markers after age 50.
Traps: a normal CT within hours does not exclude subarachnoid hemorrhage; a sentinel bleed may precede a major rupture by days.
Rule of thumb: any first or worst headache, or new headache after age 50, requires imaging and consideration of vascular and inflammatory causes.