Blood pressure readings have two numbers. The top one is your systolic number (the pressure in your blood vessels when your heart contracts). The bottom one is your diastolic number (the pressure in your arteries when your heart relaxes between beats). The two numbers together show whether your blood pressure is healthy or unhealthy. A high systolic (130 and over) or diastolic (80 and over) can count as high blood pressure. But healthy numbers may also be different for adults, children, and pregnant women.
Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19):e127-e248. PMID: 29146535 www.ncbi.nlm.nih.gov/pubmed/29146535.