Bests & Worsts Reviews from Amazon

Some previous reviewers have pointed out that the readings can be off. But I bought it anyway because majority of reviewers gave it a good rate. It turned out to be a bad decision. I have used it for a week and the numbers I got are significantly higher than my latest reading in my doctor's office. Finally I walked into a medical office inside my company and they compared the readings with the readings from their machine. In worst case, I got 149/86 from my monitor and 122/76 from theirs. What the hack! I have to return it.