For 7 years I was on 2mg of Perindopril plus 2.5 mg Bendrofluemethazide. Every time my reading was perfect. I had to change GP on moving house and my BP started creeping up. My new GP upped the Perindopril to 4 mg, then later 8 mg. Last year my diabetic check-up showed that my kidney function was not 100%, so the water tablets were stopped. I have never felt right since. My previous GP used an old-fashioned sphygmomanometer, inflated with a bulb. I don't trust these new electronic jobs, no matter how much they protest that they are regularly calibrated.