Common Causes
Tension, dehydration, lack of sleep, and migraine are frequent causes.
Other Causes
Sinus infection, eye strain, or, rarely, more serious underlying conditions.
When Urgent Care
A headache that is sudden and severe, or comes with a stiff neck and fever, needs urgent evaluation.
Emergency Warning Signs
Sudden "worst headache of your life", headache after a head injury, or headache with confusion or weakness.
Evaluation
A clinician will ask about pattern, triggers, and associated symptoms; imaging is used selectively.
Self Care
Rest in a quiet, dark room, stay hydrated, and consider an over-the-counter pain reliever.