Digital Speaking Portable smart Online Blood Pressure Monitor Check Machine Upper Arm

Blood pressure is the pressure exerted by circulating blood upon the
walls of blood vessels, which refers to systolic pressure and diastolic
pressure. Systolic pressure is the highest pressure output by blood
during systole. Diastolic pressure is the lowest pressure that blood flow
back to heart during diastole.
Change of blood pressure
Blood pressure is not constant, it is influenced by season, time,
emotion, sport, alcohol, tobacco, coffe, medicine etc, therefore, the
result will be more accurate when you measure blood pressure in a
quite environment and physical comfort.