Is it Normal for Blood Pressure to Change During the Day?

Daily Blood Pressure Fluctuations Can Mean Several Things

A senior man checks his blood pressure.
A senior man checks his blood pressure. YinYang/E+/Getty Images

Some variation in blood pressure during the day is normal, but extreme swings might indicate another problem that needs to be addressed. There usually aren't any symptoms associated with these changes in blood pressure, so detecting them can be difficult. Learn how to tell if your blood pressure swings are real, and what to do about them.

How Do You Know Your Blood Pressure is Fluctuating?

First, it’s important to make sure that your blood pressure really is fluctuating a lot during the day.

In other words, how do you know this is the case?

If you’ve made the measurements yourself using home monitoring equipment or the machines commonly found in grocery stores and pharmacies, the changes you’ve seen might actually be related to errors and/or variations in the measurement process itself.

While home blood pressure monitoring can be an effective and useful tool in some situations, you need proper training to ensure you're using the correct technique; performing the measurements without this training might explain the variation you see.

Drugstore machines -- the kind that require you to sit in a chair and put your arm through a cuff -- are notorious for being poorly calibrated and fairly inaccurate. These measurements should never be used as an indication that something is wrong, or as reassurance that everything is OK.

Normal Changes in Blood Pressure

Once you’ve verified that the fluctuation is real, understand that some fluctuation in blood pressure is completely normal.

Changes of 25 to 30 percent during the day are not abnormal -- they reflect the fact the body is a dynamic, changeable organism.

Many normal things can have large effects on blood pressure, such as:

  • How well you slept last night

When to See a Doctor

If you’re sure that the measurements are accurate, and the blood pressure swings happen even when you’re relaxed, well-rested, and have no reason that can account for the changes, go see a doctor.

Chances are that everything is OK and that the variations are just a natural part of your body’s cycle. Even if the fluctuation is not completely normal, the odds are that the exaggerated variance is the result of mild to moderate high blood pressure that hasn’t yet been diagnosed; that should fade with proper treatment and management.

When Fluctuations Mean Something is Wrong

Sometimes, wide fluctuations in blood pressure can be a signal that something else is wrong. Blood pressure swings in the absence of explainable baseline high blood pressure can indicate problems with the kidneys, heart, or blood vessels. They can also be a sign of hormone problems and certain types of tumors, such as pheochromocytoma. All of these conditions are rare.

If you’re concerned, the bottom line is that you should be evaluated by a physician. He’ll be able to tell you if the changes are real, what they mean, and what to do about them. Even if some abnormality is discovered, being in the care of a doctor already puts you on the right track.


Kaplan, NM. Clinical hypertension 8th ed. Philadelphia, Lippincott Williams & Wilkins, 2002.

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