If you have high blood pressure, evidence-based guidelines advise keeping your blood pressure lower than:
150/90 mm Hg if you’re a healthy adult 60 or older
140/90 mm Hg if you’re a healthy adult younger than 60
140/90 mm Hg if you have diabetes or kidney disease
Blood pressure that is consistently higher than normal can stretch out arteries, making them weaker and more prone to rupture, and to scarring and stiffening that sets the stage for artery-clogging atherosclerosis.
Source: Mayo Clinic Health Letter March 2015