It's normal for blood pressure to change frequently throughout the day. Several things can cause a person's blood pressure to change within just a few minutes, including:
Posture
Amount of tension
Level of exercise
Nicotine use.
Due to these normal fluctuations, it is best to use more than one blood pressure reading to figure out your average blood pressure.
Because blood pressure can run high or low in families, normal blood pressure varies from person to person. It's important to look at your overall health, lifestyle, diet, and family history when comparing your blood pressure to what's considered normal. These factors may cause you to have a higher or lower blood pressure than what's considered normal for adults.
(Click Blood Pressure Numbers to learn more about what is considered normal blood pressure for adults.)