Headache on one side of the head: possible causes

Describe whether pain is pressure, throbbing, stabbing, or burning, and whether it stays in one place or spreads. Migraine may be one-sided and may include nausea or sensitivity to light and sound. Neck, scalp, or jaw tension may cause a tight or aching sensation. Nasal blockage and facial pressure can accompany allergic rhinitis, a common cold, or chronic sinusitis.

Fever, body aches, vomiting, diarrhoea, heavy sweating, or limited fluid intake can change the assessment. These features may occur with COVID-19, dengue fever, dehydration, or heat exhaustion. A one-sided headache does not by itself show which condition is present.

Move to a quiet, cooler place, drink fluids gradually, and eat a light meal if you have not eaten. Relax your shoulders and jaw, limit bright light, and take breaks from close screen work. Keep a simple headache diary with sleep, meals, fluids, heat exposure, stress, medicines, and symptoms.

If you use a non-prescription pain reliever, follow the package directions and check with a pharmacist if you have chronic illness, take regular medicines, or are pregnant. Seek a routine appointment when episodes recur or their pattern changes.

Call emergency services for a sudden severe headache, new weakness, numbness, confusion, trouble speaking, fainting, seizure, or new vision loss. Urgent assessment is also needed for headache after injury, or a stiff neck with fever and marked illness.

Get same-day advice when headache is worsening with fever, repeated vomiting, a rash, severe light sensitivity, or signs of dehydration. A clinician should review persistent or frequently recurring pain even when no emergency sign is present.

Ask what headache pattern fits your symptoms, whether your neck, jaw, eyes, sleep, hydration, or medicines could contribute, what prevention steps to try, and which changes require urgent review.