Why doesn’t my blood pressure appear until I have taken 3 days of readings?

Because blood pressure may vary between measurements, studies have shown that even when adhering to a twice daily monitoring schedule, fewer than 3 days of readings does not provide adequate data to assess blood pressure. The American Heart Association recommends a minimum of 3 days of readings (12 readings total, 2 readings taken one minute apart every AM and PM for 3 days) and optimally 7 days(28 readings total) to properly assess blood pressure.