PATHWAYHeadache pattern finder
ICHD-3matches features to criteria to narrow the differential. Not a diagnosis.
Step 1 of ~6 · Safety check
Before pattern-matching: any of these red flags?
Read the list. These point to a secondary cause that needs workup before any pattern fits.
SNNOOP10 warning signs
- Thunderclap onsetSudden, peak in seconds
- Focal neurologic deficit or seizureNew weakness, aphasia, vision change
- Fever, weight loss, or systemic illnessConstitutional symptoms
- History of cancer (neoplasm)Risk of brain metastasis
- First-ever headache after age 50New onset late in life (giant cell arteritis)
- Recent pattern changeDifferent from prior headaches
- Progressive or worsening courseSteadily worsening, atypical
- Worse upright, relieved lying flatOrthostatic → spontaneous intracranial hypotension (CSF leak)
- Worse lying down, on waking, or with ValsalvaRecumbent-worse → raised intracranial pressure (mass, IIH, CVST)
- Triggered by cough, sneeze, or exerciseValsalva manoeuvre
- Papilloedema on examOptic disc swelling
- Painful red eye with autonomic featuresConsider acute angle-closure glaucoma
- Pregnancy or postpartumIncludes 6 weeks postpartum
- Posttraumatic onsetFollows head injury
- Immunosuppression, HIV, or cancer historyRisk for opportunistic causes
For reading, not selecting. SNNOOP10 warning signs (Do et al. 2019).