Headaches attributable to infectious diseases.

Headache is the most common symptom that humans experience. While the vast majority of headaches are due to benign primary headache disorders, a small but important minority of headaches are due to secondary causes. Whereas significant emphasis is placed on educating physicians regarding prompt recognition of subarachnoid hemorrhage and headaches secondary to brain tumors, attention toward headaches secondary to infectious causes is often neglected. Unfortunately, a missed or delayed diagnosis of a headache secondary to meningitis, encephalitis, brain abscess, subdural empyema, or other infectious etiologies can lead to dire consequences for both the patient and physician. Accordingly, this article provides an overview of headaches attributed to systemic and intracranial infectious causes.