Blood pressure: accurate measurement and safe follow-up

Systolic pressure, the upper number, is the pressure when the heart contracts; diastolic pressure, the lower number, is between beats. Results are recorded in mmHg. High blood pressure often has no symptoms; headache or nosebleeds are not a reliable way to detect it.

Office and home readings can differ; repeated measurements or day-long monitoring may be requested. Diagnosis and treatment targets depend on the setting and individual risks. High readings should not simply be accepted as normal with age. Children and pregnancy need different assessment; adult warnings here are not the only criteria.

Reducing salt, suitable activity, stopping smoking and medicines when needed may form part of your plan. A low reading is not always disease, but repeated dizziness or fainting needs assessment. Do not stop medicine just because a reading looks good, or increase fluid or salt yourself, particularly with heart or kidney disease.

Call 112 without waiting for a reading for chest pain, severe difficulty breathing, sudden speech or vision changes or one-sided weakness. In a non-pregnant adult, systolic pressure reaching/exceeding 180 or diastolic reaching/exceeding 120 mmHg with these symptoms is an emergency; do not wait for it to fall on its own.

If there are no symptoms, sit quietly and repeat after at least one minute; if readings remain this high, contact a health professional promptly. Do not take extra medicine or someone else’s under-the-tongue tablet. During pregnancy or after birth, seek urgent assessment for high readings, severe headache or vision changes without waiting for these thresholds.