30% to 40% of blood pressure cuffs are inaccurate by 4 mm hg. 10% are inaccurate by 10 mm hg or more. in other words, they show your blood pressure is higher than is actually the case, which may mean that you get prescribed blood pressure medication that you don't need. solution? get your blood pressure taken by 2 different cuffs and have the tech compare them.

in the united states, 1 in 5 hospital scales are inaccurate. in the u.k., it's 1 in 3.