Blood pressure can vary throughout the day according to your body's 24-hour cycle. This is especially helpful to be aware of when monitoring your blood pressure for health reasons.
The circadian rhythm is the "human clock" and describes the body's biological rhythms throughout the day. This can affect all of your body's vital functions, including your heart rate and blood pressure.
Day Time Blood Pressure
For most people, your body's blood pressure rises during the morning hours and reaches its highest point around midday. This is because your body is preset to increase its functions for anticipated daily activity.
Night Time Blood Pressure
Your body reaches its lowest blood pressure at bedtime, between 8 p.m. and 2 a.m. During the early hours of the morning, your blood pressure starts to increase and continues to rise to reach its peak around midday.
If you take your blood pressure midafternoon and then in the evening, you may see between a 15 to 20 mg decrease. This isn't always the case, as you will see less of a decrease in the two if you have normal blood pressure.
The circadian rhythm is currently being researched as to the effect it might have on when to start medication and certain treatment for people with high blood pressure and other heart problems. Since heart rate and blood pressure both increase and decrease with the cycle, it may be pertinent to give treatment or medication at the body's resting state.