500
The SNOOP criteria for headache red flags include these
What are
Systemic symptoms, illness, or condition (eg, fever, weight loss, cancer, pregnancy, immunocompromised state including HIV)
●Neurologic symptoms or abnormal signs (eg, confusion, impaired alertness or consciousness, papilledema, focal neurologic symptoms or signs, meningismus, or seizures)
●Onset is new (particularly for age >40 years) or sudden (eg, "thunderclap")
●Other associated conditions or features (eg, head trauma, illicit drug use, or toxic exposure; headache awakens from sleep, is worse with Valsalva maneuvers, or is precipitated by cough, exertion, or sexual activity)
●Previous headache history with headache progression or change in attack frequency, severity, or clinical features