Blood pressure looks wonderfully straightforward: cuff on, button pressed, two numbers appear. But the numbers are surprisingly sensitive to what happens in the few minutes before and during the measurement. The size of the cuff, the position of your feet, whether you have just rushed upstairs and even whether you are chatting can influence a reading. When blood-pressure decisions are based on relatively small differences, technique matters. On this page 1. The cuff is wrong for your arm 2. You skipped the quiet five minutes 3. Coffee, smoking or exercise was too recent 4. Your bladder is full 5. Your sitting position is working against you 6. Your arm is hanging below heart level 7. You are talking, scrolling or watching something How to get a more useful home record 1. The cuff is wrong for your arm ...