:red_flag: Red flags
Systemic: Fever, Weight Loss, Cancer, Immunocompromised.
Neurologic: Confusion, Altered mental status, Papilledema, Focal signs, Meningismus, Seizures.
Onset: New (esp age>40yo), Sudden (Thunderclap)
Other: Trauma, Drug use, Onset of headache with exertion, cough or sexual activity.
Previous headache hx with changes in freq, severity, clinical features.