I read an article saying almost a third of the world's population suffers from white coat syndrome. In the UK you have to wear a BP monitor for 24 hours so the doctor has an accurate reading before he prescribes medication. My reading at the Thai dentist was 156/101 (I was there for root canal work) but my reading at home was 128/81 and 126/83 - I have two machines (Omron and Kinetik) The correct way to monitor your BP is to take the reading at the same time every day (doesn't matter what time). The cuff should be at the same height as your heart and your feet should be flat on the ground with you sitting upright. There should be silence with no outside stimuli. Take 3 readings about 3/5 minutes apart and add them together and divide by 3. This will give you your mean BP and it will be far more accurate than the near useless static machines they use in Thai hospitals.