Measuring blood pressure accurately begins with the correctly sized cuff
- Begin by measuring the patient’s mid upper arm circumference.
 - Using the sizing chart below, determine what size cuff should be used based on the measurement reading. If a patient’s cm measurement is overlapping between sizes, default to the larger cuff if width is appropriate.
 - Place the artery mark located on the cuff over the patient’s brachial artery.
 - Wrap the cuff snugly and securely, allowing space for two fingers to fit between patient and cuff.
 
Infant: range 8-13 cm
Child (also available in long size): Range 12-19 cm
Small Adult (also available in long size): Range 17-25 cm
Adult (also available in long size): Range 23-33 cm
Large Adult (also available in long size): Range 31-40 cm
Thigh: Range 38-50 cm
Common sources of error in blood pressure monitoring 1
- False high, cuff error type:
- Inflatable portion of cuff too narrow
 - Inflatable portion of cuff too short
 - Cuff too loose or uneven
 - Cuff deflated too slowly (Diastolic)
 - Cuff overinflated
 - Cuff inflated too slowly (Diastolic)
 
 - False high, human error type:
- Recording BP immediately after meals, while smoking or with distended bladder
 - Patient’s arm below level of heart
 
 - False low, cuff error type: 
- Cuff too wide
 
 - False low, human error type:
- Patient’s arm above level of heart
 - Failure to notice auscultatory gap
 - Inability to hear feeble Korotkoff sounds
 - Failure to have meniscus of mercury at eye level
 - Stethoscope bell applied too firmly
 
 - False high or low, human error type:
- Caregiver’s error
 - Cuff deflated too fast
 
 
Using the WRONG SIZED BLOOD PRESSURE CUFF can affect accuracy UP TO 30 mmHG2 . The American Heart Association recommends that a cuff bladder width be 40% of the arm circumference and that a cuff bladder length be 80% of the arm circumference.1
Reference:
- Pickering, T., et al Recommendations for Blood Pressure Measurement in Humans: An AHA Scientific Statement from the Council on High Blood Pressure Research Professional and Public Education Subcommittee. Hypertension 45, 142-161 (2005).
 - Manning, D.M., et al Miscuffing: Inappropriate blood pressure cuff application. Circulation 68(4), 763-6 (1983).