Blood pressure is measured using a cuff placed on one arm. This cuff has to be fit properly to ensure accurate readings and to determine whether the readings are normal or if you need medical assistance. The cuff inflates with a hand pump or a machine, which can be referred to as an automatic blood pressure reading. The arm with the higher reading should then be used. https://sahyadrihospital.com/blog/how-is-blood-pressure-diagnosed/