A 34-year-old man wakes up at 2am with severe right-sided pain behind the eye, lasting about an hour. His right eye is tearing, the lid is drooping, and the right nostril is running. He has had this happen every night for the past week. Vitals normal. Neuro exam normal.
What is the most likely diagnosis?
Migraine with aura
Cluster headache
Tension headache
Temporal arteritis
Subarachnoid hemorrhage
Strictly unilateral, behind-the-eye, short attacks at the same time every night, with same-side autonomic features (tearing, ptosis, rhinorrhea) = cluster.
Migraine is throbbing, longer (4 to 72h), often with nausea and aura, and lacks the autonomic same-side eye signs. Tension is bilateral and band-like with no autonomic features. Temporal arteritis hits older patients with jaw claudication and scalp tenderness. SAH is sudden thunderclap, not nightly clockwork.
The nightly clockwork plus ipsilateral autonomic signs seals it. Acute move: 100% oxygen, triptan. Prevent next cluster: verapamil.
Five syndromes side by side
Sweep across the columns. Notice what changes: location, quality, the giveaway clue, what you do. On phones, each column becomes its own card.
Tap a card to flip it. Front: the patient. Back: the clue cluster, the diagnostic move, the drug of choice.
💥
Cluster
Man, 34. Severe right-eye pain at 2am, lasting one hour. Same time, every night this week.
Tap to flip
Cluster headache
Clue clusterStrictly unilateral pain behind the eye, plus ipsilateral tearing, ptosis, rhinorrhea. Attacks come in clusters, weeks at a time, same hour of the night.
Diagnostic moveClinical diagnosis from the pattern. Imaging only if focal neuro deficit or atypical features.
Drug of choiceAcute: 100% O2 by mask, plus triptan. Prevention: verapamil.
Tap to flip back
🧠
Tension
Woman, 41. Bilateral pressure across the forehead after a long shift. No nausea, no aura.
Tap to flip
Tension headache
Clue clusterBilateral, frontal, band-like pressure. Mild to moderate. No nausea, no vomiting, no autonomic features. That negative pattern is the giveaway.
Diagnostic moveClinical. No imaging unless red flags. Look for sleep deprivation, stress, jaw clenching, posture.
Drug of choiceAcute: NSAID or acetaminophen. Chronic: lifestyle, plus amitriptyline if frequent.
Tap to flip back
🌙
Migraine
Woman, 28. Right-sided throbbing for the last 12 hours. Nauseated. Saw zigzag lights before it started.
Tap to flip
Migraine
Clue clusterUnilateral, throbbing, lasting 4 to 72 hours, disabling. Nausea plus or minus aura (scintillating scotomas, hemianopia, marching paresthesias).
Diagnostic moveClinical from history. Image only if first or worst, focal deficits, age >50 with new pattern, or red flags.
Drug of choiceAcute: triptan, NSAID, antiemetic, oxygen. Prevention: propranolol, topiramate, amitriptyline, CGRP antagonists.
Tap to flip back
⚠️
Temporal arteritis
Woman, 72. New left-temple headache for two weeks. Jaw hurts when she chews. Scalp tender. Brief vision blur this morning.
Tap to flip
Giant cell arteritis
Clue clusterNew headache in >50yo, unilateral temple, plus jaw claudication, scalp tenderness, ESR markedly elevated. Often overlaps with polymyalgia rheumatica.
Diagnostic moveSend ESR and CRP. Start IV steroids immediately if vision threatened. Temporal artery biopsy confirms, but treat first. Don't wait.
Drug of choiceHigh-dose glucocorticoids (IV methylprednisolone for vision threat, oral prednisone otherwise). Vision loss is permanent if missed.
Tap to flip back
⚡
SAH
Man, 49. Sudden “worst headache of my life” while lifting a weight. Vomits. Neck stiff. Hates the light.
Tap to flip
Subarachnoid hemorrhage
Clue clusterThunderclap onset, “worst headache of life,” often with neck stiffness, photophobia, vomiting. Sometimes a sentinel bleed in the days before. Ruptured berry aneurysm at anterior communicating artery is the classic.
Diagnostic moveNon-contrast CT head emergent. Sensitivity drops after 6 hours, so if CT is negative and suspicion is high, do an LP looking for xanthochromia.
Drug of choiceNimodipine to prevent vasospasm. Neurosurgery or endovascular team for clipping or coiling the aneurysm.
Tap to flip back
“Worst headache of my life”: red flags game
Same chief complaint, three different patients. Pick the diagnosis. The thunderclap goes to CT NOW.
Why cluster makes the eye cry, droop, and run
Cluster fires the trigeminal-autonomic reflex: V1 pain on one side, parasympathetic spillover on the same side. Tracing of canonical anatomy, not a memory sketch.
V1 painThe trigeminal first division. Forehead, scalp, eye. Cluster lights it up on one side.
Ptosis & miosisSympathetic underdrive at the lid and pupil on the same side. Looks like a partial Horner’s.
LacrimationParasympathetic overdrive at the lacrimal gland. Tears stream on the painful side.
RhinorrheaParasympathetic overdrive at the nasal mucosa. Same-side nostril runs.
Red Flag Sorting
Do not start with the headache name. Start with danger: thunderclap onset, age over 50, focal neurologic deficit, fever or neck stiffness, papilledema, pregnancy, cancer, immunosuppression, and exertional or sexual trigger. Primary headaches are pattern diagnoses only after dangerous secondary causes are excluded.
!
Board move: worst headache with meningismus after negative CT still needs lumbar puncture for xanthochromia when suspicion stays high.
Clinical Images
Migraine aura · visual cortex symptom · tap to expand
Circle of Willis · aneurysm geography · tap to expand
SAH CT · blood in CSF spaces · tap to expand
SAH: what the bleed looks like
Real non-contrast CT on the left. Schematic of where the blood pools on the right. Captions only, no overlays on the real image.
Tap to expand
Non-contrast CT · subarachnoid blood
Bright white (high attenuation) in the spaces that should be black: basal cisterns, sylvian fissures, interhemispheric fissure. Sensitivity drops after the first 6 hours as blood breaks down. Negative CT plus high suspicion = LP for xanthochromia.
Wikimedia Commons
Where the blood pools
The CSF cisterns become bright white: midline interhemispheric fissure, both sylvian fissures, basal cisterns at the floor of the skull. The yellow dot marks the anterior communicating artery, the most common berry aneurysm site.
Temporal arteritis: steroids first, biopsy after
The single rule. Don't let imaging or pathology slow you down. Vision loss in this disease is permanent.
Don't miss this one
New unilateral temporal headache in someone over 50? Treat first. Confirm later.
If the patient has any vision change (transient monocular blindness, double vision, blur), give IV methylprednisolone right now. Don't wait for the ESR. Don't wait for the temporal artery biopsy. Don't order an MRI first.
Biopsy results stay positive for up to two weeks after starting steroids, so you don't lose the diagnosis by treating. You DO lose the eye if you wait.
1High-dose steroids the moment you suspect it. IV if vision symptoms, oral prednisone otherwise.
2Send ESR and CRP. ESR is classically >50, often >100, but a normal ESR does not rule it out.
3Temporal artery biopsy within 1 to 2 weeks. Skip lesions are real, so a long segment is sampled.
4Long taper, monitor for steroid side effects, screen for thoracic aortic aneurysm down the line.
Six-question pattern check
One vignette per syndrome, plus a differentiator. Pick the answer, read the why.
clinical Walkthrough
clinical Walkthrough
Original clinical vignettes. Shuffled, never-repeat, full explanations for every choice.
Medically reviewed by Kaitlyn Cocuzzo, MD and Fatima Ali, DO · Last reviewed June 2026
Bone Wizardry is an independent educational resource for visual learning in the medical sciences. It is not affiliated with, endorsed by, or sponsored by any licensing or examination board, contains no real or recalled examination questions, and does not guarantee any educational or examination outcome.
