Blood pressure is written as two numbers, such as 112/78 mm Hg. The top (systolic) number is the pressure when the heart beats. The bottom (diastolic) number is the pressure when the heart rests between beats. Normal blood pressure is below 120/80 mm Hg.
If you’re an adult and your systolic pressure is 120 to 139, or your diastolic pressure is 80 to 89 (or both), you may be told you have “pre-hypertension.” High blood pressure is considered to be a pressure of 140 systolic or higher and/or 90 diastolic or higher that stays high over time.
High blood pressure usually has no signs or symptoms. About one in three adults has it, and many don’t know they have it. Not treating high blood pressure increases the risk of heart attack and stroke. Get your blood pressure checked regularly and see your doctor to discuss treatment options if you have high blood pressure.
— Source: American Heart Association