Hello chris5,,,,thank you for the explanation,,and this gives me so information as to why my readings are higher some mornings than others,,,,I just thought it was my late nights,,and sleeping at different times of the day,,,,go to bed at 6am and get up between 10 and 12,,,,so I will have to watch what I eat at night,,and go to bed earlier,,and have more sleep,,,,if that is possible when the dog comes into my room and jumps up onto my bed,,,then nudges me to move over as he wants to get in my bed,,,and have a sleep with me,,,,then the cats come wanting their breakfast,,,no wonder my readings are very varied,,,,,,ttfn from Karen.