Headache persistent for days: what to know

A lingering headache can follow a viral illness, nasal inflammation, poor sleep, stress, dehydration, heat exposure or an irregular eating pattern. Allergic rhinitis, a common cold, COVID-19 and chronic sinusitis may bring congestion or facial pressure. Migraine can last beyond the initial severe phase and may leave fatigue or sensitivity to light. Taking pain medicines repeatedly can also make headaches recur or become harder to settle. The duration is useful information, but it does not reveal the cause by itself. Note whether the pain is constant or comes in waves, where it is felt, and what changes it.

Arrange a clinician review for a new headache that has continued for days, particularly when usual self-care has not helped. Until then, keep a steady sleep routine, drink fluids, eat regularly and take quiet breaks from screens. Avoid excess heat and alcohol. Use pain relief only according to the product directions; do not combine products with the same ingredient, and ask a pharmacist if you take regular medicines or have kidney, liver, stomach or bleeding problems. Bring a list of medicines and a brief symptom diary to the appointment.

Seek emergency help for a sudden explosive headache, weakness or numbness, confusion, fainting, seizure, trouble speaking, or fever with a stiff neck. Obtain urgent assessment for new vision loss, double vision, severe eye pain, repeated vomiting, a headache after head injury, or a rapidly worsening pattern. Fever with marked illness after travel or a possible mosquito exposure also warrants prompt medical advice.

What features of my history suggest migraine, infection, dehydration or another cause? Do I need an eye or neurological examination? Could any medicine be prolonging the pain? What changes should prompt emergency care?