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.
If the top number stays high, or the bottom number stays high, or both, that means you have high blood pressure (hypertension). It's normal for blood pressure to go up and down throughout the day. Your doctor will give you a goal for your blood pressure.
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:
- You passed out (lost consciousness).
Call your doctor now or seek immediate medical care if:
- Your blood pressure is much higher than normal (such as 180/120 or higher).
- You think high blood pressure is causing symptoms such as:
- Severe headache.
- Blurry vision.
- You are dizzy or lightheaded, or you feel like you may faint.
Watch closely for changes in your health, and be sure to contact your doctor if:
- Your blood pressure measures higher than your doctor recommends at least 2 times. That means the top number is higher or the bottom number is higher, or both.
- You think you may be having side effects from your blood pressure medicine.
Credits
Current as of: March 9, 2022
Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD
- Internal Medicine
Martin J. Gabica MD - Family Medicine
Adam Husney MD - Family Medicine
WHEN SHOULD I WORRY ABOUT...
Dec. 11, 2019
When was the last time your blood pressure was checked?
It's important to keep tabs on your blood pressure numbers since having high blood pressure increases your risk for heart disease and stroke.
“High blood pressure is sometimes called a ‘silent killer’ because it doesn’t cause symptoms and won’t be caught without regular blood pressure readings,” explains Dr. Irfan Dadabhoy, primary care physician at Houston Methodist.
It's also a common health condition. In fact, millions of American adults have high blood pressure, many of whom don't have it under control.
What is high blood pressure?
Blood pressure is a measurement of the force of your blood pushing against your blood vessel walls. High blood pressure, or hypertension, is diagnosed when that pressure is consistently too high.
Your systolic pressure (the top number of your reading) is the pressure in the arteries as the heart beats. Your diastolic pressure (the bottom number of your reading) is a measurement of the pressure in the arteries as the heart muscle rests.
“Typically, the top number receives more attention, but elevated diastolic pressure alone also increases cardiovascular disease risk,” says Dr. Dadabhoy.
There are five categories of blood pressure, and it's important not just to check your blood pressure but also know when your numbers mean it’s time to act.
Why it’s important to have your blood pressure checked
Since high blood pressure doesn't present with obvious symptoms, Dr. Dadabhoy says the only way to know whether you have it is to have your blood pressure checked.
Most likely, your blood pressure is measured and recorded every time you go to your health care provider’s office. And, keep in mind, just because you feel "healthy" doesn't mean you can ignore your doctor's warnings about elevated blood pressure. Everyone's blood pressure matters, even if you're young.
It's important to talk with your doctor about what your blood pressure numbers mean for your personal health. If your numbers are elevated or high, don't wait to start making the lifestyle changes needed to lower your blood pressure and keep the issue from progressing. And work with your doctor to understand whether additional measures are needed, such as medications.
Tips for managing high blood pressure
“There’s no cure for high blood pressure, but you can successfully manage it with medication and living a healthy lifestyle,” Dr. Dadabhoy says.
The following changes can help you better manage high blood pressure:
- Monitoring your blood pressure regularly
- Taking your medications as prescribed
- Eating a well-balanced, low-salt diet
- Exercising regularly
- Maintaining a healthy weight that you and your doctor have agreed on
- Quitting smoking
- Increasing potassium intake, if recommended by your doctor
- Managing stress
- Limiting alcohol