Give d/d of headache
Reading File
Searching for differential diagnosis of headache across primary and secondary categories.
search_medical_text
differential diagnosis of headache primary secondary causes
Management of Headache
Page 30
search_medical_text
headache red flags serious secondary causes meningitis subarachnoid hemorrhage hypertension
Harrison's Principles of Internal Medicine, Twenty First Edition
Page 572
GradeResponse
GradeResponse
Differential Diagnosis of Headache
Headaches are broadly classified into Primary (no underlying structural/systemic cause) and Secondary (due to an identifiable underlying disorder).
PRIMARY HEADACHE DISORDERS
These are diagnoses of exclusion after ruling out secondary causes.
| Type | Key Features |
|---|---|
| Migraine | Unilateral, pulsating, moderate-severe intensity; nausea/vomiting; photophobia/phonophobia; lasts 4–72 hrs; may have aura (visual scotoma, zigzag lines) |
| Tension-Type Headache (TTH) | Bilateral, "band-like" pressure; mild-moderate; no nausea/vomiting; not aggravated by physical activity |
| Cluster Headache | Unilateral, periorbital/temporal; severe, "boring/stabbing"; autonomic features (lacrimation, rhinorrhea, ptosis, miosis); lasts 15–180 min; occurs in clusters |
| Chronic Daily Headache | Headache ≥15 days/month for >3 months |
| Hemicrania Continua | Continuous, unilateral; responsive to indomethacin |
| New Daily Persistent Headache (NDPH) | Daily from onset, no prior headache history |
| Primary Cough/Exertional/Sexual Headache | Triggered by Valsalva, exercise, or sexual activity |
SECONDARY HEADACHE DISORDERS
Per ICHD-3 criteria, a secondary headache develops in temporal relation to an underlying causative disorder (Management of Headache, p. 30).
🔴 EMERGENT / LIFE-THREATENING
| Cause | Key Features |
|---|---|
| Subarachnoid Hemorrhage (SAH) | "Thunderclap" headache — worst headache of life, sudden onset; nuchal rigidity; LP shows xanthochromia |
| Bacterial Meningitis | Fever + headache + neck stiffness + photophobia; Kernig's/Brudzinski's sign positive |
| Hypertensive Emergency | BP >180/120; pulsating headache; papilledema; encephalopathy |
| Cerebral Venous Sinus Thrombosis (CVST) | Progressive headache, seizures, focal deficits; hypercoagulable states |
| Epidural/Subdural Hematoma | Trauma history; lucid interval (epidural); progressive drowsiness |
| Brain Abscess | Fever, focal deficits, raised ICP; subacute onset |
| Acute Angle-Closure Glaucoma | Severe orbital pain; halos around lights; fixed mid-dilated pupil; nausea/vomiting |
⚠️ SERIOUS (URGENT)
| Cause | Key Features |
|---|---|
| Intracranial Tumor | Progressive, worse in morning/lying down, aggravated by Valsalva; focal deficits; papilledema |
| Idiopathic Intracranial Hypertension (IIH) | Obese young women; pulsatile tinnitus; visual changes; papilledema; high CSF opening pressure |
| Temporal (Giant Cell) Arteritis | Age >50; temporal artery tenderness; jaw claudication; elevated ESR/CRP; risk of blindness |
| Carotid/Vertebral Artery Dissection | Neck pain; Horner's syndrome; focal neurological deficits |
| Carbon Monoxide Poisoning | Multiple people affected; exposure history; cherry-red skin |
NON-URGENT SECONDARY CAUSES
| Cause | Key Features |
|---|---|
| Sinusitis | Facial pain/pressure; purulent nasal discharge; tenderness over sinuses |
| Cervicogenic Headache | Neck pain/stiffness; restricted cervical ROM; referred from C1-C3 |
| Post-traumatic Headache | Follows head injury; onset within 7 days |
| Medication Overuse Headache (MOH) | >10–15 days/month analgesic use; rebound headache |
| Viral Meningitis | Self-limited; less toxic than bacterial |
| Hypothyroidism | Diffuse headache; other features of hypothyroidism |
| Sleep Apnea Headache | Morning headaches; improves after waking |
| Dental/TMJ Disorders | Temporal/preauricular pain; aggravated by jaw movement |
| Anemia / Hypoxia | Diffuse; associated systemic features |
| High-Altitude Headache | Recent ascent; resolves with descent/oxygen |
RED FLAGS ("SNOOP4" Mnemonic)
Per Harrison's (p. 572), new-onset severe headache demands urgent evaluation:
| Letter | Feature |
|---|---|
| S | Systemic symptoms (fever, weight loss) or Secondary risk factors (HIV, malignancy) |
| N | Neurological symptoms or signs (confusion, focal deficits, papilledema) |
| O | Onset sudden / thunderclap |
| O | Older age (>50 — think GCA, tumor) |
| P | Progressive headache, or Positional change |
| P | Precipitated by Valsalva/cough/exertion |
| P | Pregnancy or postpartum |
| P | Prior headache history — change in pattern |
Any red flag warrants urgent neuroimaging (CT/MRI) ± LP before attributing to a primary disorder.
This is a shared conversation. Sign in to Orris to start your own chat.