Caffeine and headaches: what should you know?

Caffeine affects blood vessels and the nervous system, so the same drink may feel helpful at one time and unhelpful at another. Some headache medicines include caffeine because it can support pain relief. Repeated use can create a pattern in which missing the usual drink is followed by headache, tiredness or difficulty concentrating. Large amounts may also disturb sleep, increase anxiety or make it harder to notice dehydration. Headache can occur with a common cold, allergic rhinitis, sinus disease or other illnesses, so caffeine timing alone does not identify the cause.

Record when the headache begins, what caffeine you had, sleep, meals, heat exposure and any pain medicine. Keep hydration and regular meals in your routine. If you plan to cut down, reduce gradually rather than stopping suddenly after regular use. Check combination pain medicines carefully, because taking several products with caffeine or using pain relief frequently can maintain a headache cycle. Rest in a quiet, dim room and follow the label or your clinician's directions for medicines.

Get urgent help for a sudden severe headache, a new headache with weakness, confusion, fainting, stiff neck, repeated vomiting, vision loss or trouble speaking. Seek prompt advice for headache with high fever, a new rash, recent head injury, pregnancy or significant heat exposure. Arrange a review when headaches recur, change pattern, wake you from sleep or require frequent pain medicine.

Ask whether your pattern suggests withdrawal, migraine, infection or another cause, and whether your caffeine or pain-medicine routine should change.