Blood pressure and headache: what to know

High blood pressure often causes no noticeable symptoms. Headache can occur for many other reasons, including dehydration, viral illness, nasal inflammation, heat exposure, anxiety or poor sleep. Rarely, a very high pressure can be part of a medical emergency, especially when the headache is sudden or accompanied by neurological or visual changes. A single home reading can be affected by recent activity, pain, caffeine, stress or an incorrect cuff size. The number needs context, repeated measurements and a review of your usual readings.

Rest quietly for several minutes, sit with your back supported and feet on the floor, and keep your arm supported at heart level. Use a correctly fitting cuff on bare skin and avoid talking during the measurement. Take another reading after a short rest if the first is unexpectedly high, then record the time, reading and symptoms. Continue prescribed treatment unless a clinician tells you otherwise. Drink fluids when appropriate and consider whether a cold, heat exposure or stress may explain the headache.

Call emergency services for a sudden severe headache, weakness or numbness on one side, trouble speaking, confusion, fainting, chest pain, breathlessness or new vision loss. Seek urgent assessment for a high reading that remains very elevated after repeat measurement, particularly when headache, vomiting or neurological symptoms are present. Pregnancy with a severe headache or visual symptoms also needs prompt medical advice.

Ask whether your monitor and cuff are suitable, how often to measure, and whether your medicines or another illness could be contributing to the headache. Bring your reading log and mention any visual, neurological or fever-related symptoms.