I hope this is understandable through the brain fog. An American friend with CFS posted me a video of his fitbit showing his pulse go up excessively from lying to standing. That way he realized that he had POTS and is now getting treated in Cedar Sinai hospital. I want a device I can wear that can measure both pulse rate AND blood pressure when I lie down and get up and stand. Everyone tells me something else. Some say a fitbit watch for pulse alone. Some say a fitbit is unreliable and I should get something to wear on the chest. Which is right? Does anyone have any idea for brands and devices?