Blood Pressure Basics in Physical Therapy

Whether you work with high-level athletes or high-level couch potatoes, monitoring a patient’s blood pressure at rest and during exercise can offer very useful information to a clinician. It can mean the difference between a safe and effective treatment session and a trip to the emergency room. Whether you believe it to be necessary or not, the dangers of uncontrolled and prolonged hypertension are very real.

While my intention is not to change your belief on the necessity of monitoring blood pressure, my hope is to provide both clinicians and students with some basic information on blood pressure from which they can base their own clinical decisions from. As a healthcare professional, you have a responsibility to your patient to be able to interpret blood pressure values as normal or abnormal and have an appropriate course of action in mind. I encourage interested readers to take the next step and utilize as many resources as possible to educate themselves on blood pressure (and vital signs in general) – including normal/abnormal responses to exercise, the effect of various medications, and so on.

*per the AHA SBP DBP
Normal < 120 and < 80
Prehypertension 120-139 or 80-89
Stage 1 Hypertension 140-159 or 90-99
Stage 2 Hypertension > 160 or > 100
Hypertensive Crisis > 180 or > 110

Some tips on taking blood pressure correctly and efficiently:

  • Practice, practice, practice - there is nothing worse than fumbling with a blood pressure cuff and having the gauge awkwardly dangle while you try to figure out why the squeeze bulb isn't inflating the thing past 5 mm Hg. Make sure to practice on multiple people, different arms and legs, and positions.
  • Size matters - the inflatable part of the cuff should encircle roughly 80% of the upper-arm (if this is where you will be taking your measurement from) and the width of it should cover approximately two-thirds the distance between the axilla and antecubital space. Otherwise your reading may be inaccurate:
    • If a cuff is too short/narrow: erroneously high measurement.
    • If a cuff is too long/wide: erroneously low measurement.
  • Avoid overinflating and/or keeping the cuff inflated for too long - the discomfort can cause a rise in blood pressure. The recommendation out there is to decrease the pressure at a rate of 2-4 mm Hg/second.
  • A good stethoscope goes a long way - some stethoscopes are just better than others. Plain and simple. For example - in noisy environments like most physical therapy clinics, a cheap stethoscope simply cannot pick up the sounds you're listening for as well as a well-made one. Of course you can always try to control for such variables but that is not always possible/time-efficient. If taking blood pressure is at all a normal occurrence for you, investing in a good stethoscope is a must.
  • Calibrate your manual meters - understand that aneroid sphygmomanometers (these ones) utilize a spring mechanism and may need to be periodically calibrated with a reference gauge, typically a more accurate mercury meter. Click here for instructions on how to calibrate an aneroid sphygmomanometer. Some medical supply companies also offer this service if you are not comfortable doing it yourself.
aNEROID SPHYGMOMANOMETERS ARE &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; VERY COMMONLY USED.


*Per their website, the AHA recommends that if a patient has an initial resting reading of >180 SBP and/or >110 DBP, another measurement should be taken after a few minutes to confirm. If the subsequent reading is still above this threshold, contact emergency services. If the initial high reading coincides with the symptoms in the above graphic, do not wait to take another measurement and contact emergency services immediately.

*From Watchie, J. Cardiopulmonary Physical Therapy: A Clinical Manual. Saunders, Philadelphia 1995