Blood pressure fluctuates constantly during the day. Its value in the daytime is higher than in the evening with the lowest level being at midnight. The pressure begins to rise again at 3:00am and reaches its highest level any time during the day – so it is impossible to get a consistent reading. For this reason, please take your measurements at the same time of day. Relax for 10-20 minutes before taking a measurement and remain relaxed whilst measuring. Do not move or talk during measurement, as this will affect the accuracy.