The middle part of the cuff air bag is placed above the brachial artery of the upper arm. The lower edge of the cuff is between 2 and 3cm above the cubital fossa. If the cuff is tied too tightly, the measured systolic and diastolic pressures will be low. Too loose binding can make the measured blood pressure on the high side. It is generally considered that the tightness is moderate when two fingers can be inserted.