Blood pressure

Blood pressure is written as two numbers separated by a slash, such as 120/80 mm Hg, with the systolic number first. It changes during the day with your activities. Under the levels NHLBI (page updated April 2024) and MedlinePlus give for adults: normal is systolic below 120 and diastolic below 80; systolic 120–129 with diastolic below 80 is elevated; stage 1 high blood pressure is systolic 130–139 or diastolic 80–89, and stage 2 is systolic 140 or higher or diastolic 90 or higher. Systolic above 180 or diastolic above 120 is a hypertensive crisis: contact a provider right away. NHLBI says blood pressure is high when readings are consistently at those levels; a provider will usually take two or more readings at separate appointments before making a diagnosis. For children and teens, the provider compares the reading with what is normal for their age, sex and height rather than using these cut-offs.

High blood pressure usually has no symptoms until it has caused serious health problems, so the only way to find out is regular checks; NHLBI advises having it checked at least once a year.