Why is my blood pressure so variable?


Key points

  1. Some variation in blood pressure is normal. Your Marley Medical provider will work with you to choose the right medications to keep your blood pressure controlled throughout the day.
  2. Use a home monitor to check your blood pressure. Ask your provider if you should check it at the same time each day or at different times.
  3. If you’re taking blood pressure medication, it is important to take it as prescribed, without missing doses.

Is my blood pressure supposed to vary?

You may have noticed that your blood pressure changes from reading to reading. It may even vary from second to second and minute to minute! This is called “blood pressure variability.”  Although some variability is normal, a lot of variability can be unhealthy.  Read on to find out why your blood pressure changes throughout the day and what it means.

What things can affect my blood pressure reading?

Blood leaves your heart and returns to your heart all day long. Blood pressure is the force of this blood on the walls of the arteries as it passes through them. A lot of of things in our daily life can affect your blood pressure including:

  • Your emotions
  • Environmental factors, such as time of day, season, and altitude
  • Physical factors you can change, such as your posture and how well hydrated you are, and
  • Physical factors you can’t change, such as your age, genetics,  and how stiff your blood vessels are

Because these things can change throughout the day, so does your blood pressure. Even if you’re not stressed and your environment stays the same there’s a natural rhythm that blood pressures normally follow. In general, blood pressures are lowest overnight and highest in the middle of the day.  Throughout the day, your blood pressures can be high, low, and anywhere in between.

Why does blood pressure variability happen?

We know that blood pressure is an important tool our body uses to get blood to our organs when they need it. For example, blood pressure increases when we face physical or emotional stress and decreases when we rest.  However, studies also confirm that more blood pressure variability is associated with increased risk of heart attacks, strokes, and cardiovascular death, regardless of how high or low the pressures are. Although we’re not sure exactly why, it may be that aging and stiffness of our blood vessels contribute to the variability.

Can I do anything to reduce my blood pressure variability?

It is normal for your blood pressure to be higher at certain times of the day and lower at others. Managing your stress and staying hydrated can help prevent some variability. Blood pressure medicines, in addition to lowering your blood pressure, also help reduce its variability.

Some people experience dramatic changes in blood pressure over a short period of time. These changes can cause symptoms like lightheadedness or headaches. This sudden change in blood pressure could be a sign of an underlying medical condition. If you are having symptoms related to your changing blood pressure, talk to your provider about what to do.

What you need to know

Blood pressures change throughout the day. It’s part of what makes the body such an amazing machine. Usually there is nothing to worry about, but if your blood pressure changes a lot during the day, or causes symptoms when it changes, it could mean more. That’s when it’s time to check with your healthcare provider.


  1. National Institute On Aging. High Blood Pressure and Older Adults. National Institute on Aging. Published October 27, 2021. https://www.nia.nih.gov/health/high-blood-pressure-and-older-adults
  2. Kim K, Nikzad N, Quer G, et al. Real World Home Blood Pressure Variability in Over 56,000 Individuals With Nearly 17 Million Measurements.  American Journal of Hypertension. 2017;31(5):566-573. doi:10.1093/ajh/hpx221
  3. Ebinger JE, Driver M, Ouyang D, et al. Variability independent of mean blood pressure as a           real-world measure of cardiovascular risk. eClinicalMedicine. 2022;48. doi:10.1016/j.eclinm.2022.101442
  4. Parati G, Stergiou GS, Dolan E, Bilo G. Blood pressure variability: clinical relevance and application. The Journal of Clinical Hypertension. 2018;20(7):1133-1137. doi:10.1111/jch.13304
  5. Postural hypotension what it is & how to manage IT. https://www.cdc.gov/steadi/pdf/STEADI-Brochure-Postural-Hypotension-508.pdf. Accessed August 26, 2022.
  6. What are the symptoms of high blood pressure? www.heart.org. https://www.heart.org/en/health-topics/high-blood-pressure/why-high-blood-pressure-is-a-silent-killer/what-are-the-symptoms-of-high-blood-pressure. Published June 2, 2022. Accessed August 26, 2022.

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