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Blood Pressure Numbers: When to Get Help

Table of Contents


Overview

What do your blood pressure numbers mean?

Blood pressure is a measure of the force of blood against the walls of your arteries. Blood pressure readings include two numbers. The first number is the systolic pressure (top number). This is the force of blood on the artery walls as your heart pumps. The second number is the diastolic pressure (bottom number). This is the force of blood on the artery walls between heartbeats.

It's normal for blood pressure to go up and down throughout the day. But if the top number stays high, or the bottom number stays high, or both, that means you have high blood pressure (hypertension). For diagnosis, the top number may be 130 to 140 or higher. The bottom number may be 80 to 90 or higher. 1, 2

Your doctor will give you a goal for your blood pressure. Your goal will be based on your health and your age.

What can cause blood pressure to go up or down?

It's normal for blood pressure to go up and down throughout the day. Things like exercise, stress, and sleeping can affect your blood pressure. Some medicines can cause your blood pressure to go up. These medicines include certain asthma medicines and cold remedies.

A low blood pressure reading can be caused by many things, including some medicines, a severe allergic reaction, or an infection. Another cause is dehydration, which is when your body loses too much fluid.

When should you call your doctor?

One high or low blood pressure reading by itself may not mean you need to call for help. If you take your blood pressure and it is out of the normal range, wait a few minutes and take it again. If it's still high or low, use the following guidance.

Call 911 anytime you think you may need emergency care. For example, call if:

Call your doctor now or seek immediate medical care if:

Watch closely for changes in your health, and be sure to contact your doctor if:


References

Citations

  1. Whelton PK, et al. (2017). Guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Journal of the American College of Cardiology, published online November 13, 2017. DOI: 10.1016/j.jacc.2017.11.006. Accessed November 20, 2017.
  2. Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (2003). Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure JNC Express (NIH Publication No. 03–5233). Bethesda, MD: U.S. Department of Health and Human Services.

Credits for Blood Pressure Numbers: When to Get Help

Current as of: July 10, 2023

Author: Healthwise Staff (https://www.healthwise.org/specialpages/legal/abouthw/en)
Clinical Review Board (https://www.healthwise.org/specialpages/legal/abouthw/en)
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.


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