What Your Blood Pressure Numbers Mean — and Why They Matter

October 17, 2022
William Hanner D.O.

It happens at your primary care doctor’s office… your specialist’s office… at the dentist… and maybe even when you go to the gym. Before any health treatment begins, it seems like anyone and everyone wants to take your blood pressure. 

Have you ever wondered why that is? 

While it may surprise you, this simple yet vital reading can reveal a lot about your current state of health, and what you need to do to improve your health too.

Let us take a closer look at what your blood pressure numbers mean, when your numbers indicate you may need care, and how this vital reading can impact your well-being, including how blood pressure affects you when you get surgery.

What do the numbers in blood pressure readings mean?

When someone takes your blood pressure, they are getting two numbers that relate to how well your heart is moving blood throughout your body. For example, your doctor may take your blood pressure and tell you it is “120 over 80” or 120/80 mm Hg (or millimeters of mercury, which is how blood pressure is traditionally measured). 

Let us break that down so we can understand this reading better.

What is the top number in your blood pressure reading?

The “top” number in your reading is called your systolic blood pressure — in this example, it’s the “120.” That number refers to what is happening when your heart beats. With every pulse, your heart muscle squeezes and pushes blood through your arteries, which creates pressure on the artery walls.

What is the bottom number in your reading?

The bottom number is your diastolic blood pressure — in the above example, it’s the “80.” This number relates to what happens in between each heartbeat, when your heart is at rest. During each pause between beats, your heart draws in blood and gets oxygen from it. And this creates some pressure too, though not as much as when your heart pulses. That is why this bottom number is normally lower than the top number.

What is healthy, average, and dangerous blood pressure?

Your blood pressure will vary day to day, and even time of day, as well as other factors. But in general, these vital numbers should fall within a certain range to be considered normal. If either the systolic or diastolic numbers (or both!) are outside the normal range, it is a good idea to consult with a doctor for guidance on what you may need to do.

What is considered average blood pressure?

Remember that blood pressure can change due to many factors, including age and gender (we will look at that in a moment). But even with that in mind, there is a reason that most people have heard the numbers 120/80 mm Hg. This is very close to the average blood pressure that doctors record when doing large studies.

One study (by Lancet in 2015), for example, recorded the average worldwide blood pressure as 127/79 mm Hg in men, and 122/77 mm Hg in women.

What is the “ideal” healthy blood pressure?

All things being equal, the best blood pressure measures are less than 120 mm Hg systolic, and less than 80 mm Hg diastolic. If your blood pressure is less than 120/80 mm Hg, that is great news! You can continue to follow the heart-healthy habits you probably have already adopted, such as eating fruits and vegetables, limiting processed sugar, drinking plenty of water, getting good sleep, and exercising regularly.

How do I know when my blood pressure needs attention?

If either of these numbers is higher than 120/80 mm Hg, however, your blood pressure is edging into a less than ideal reading.

Your blood pressure is considered “elevated” (aka, higher than normal) if your top number (systolic) is 120–129, but your diastolic is still safely below 80. In this condition, you are at some risk of developing high blood pressure, but actions such as improving your diet and exercising can often help.

Stage 1 hypertension (high blood pressure) is the diagnosis when one or more of these is your consistent reading:

  • A top reading of 140 or higher
  • A bottom reading of 90 or higher

At this stage, your doctor will likely recommend mitigating actions as well as possibly medication to manage your blood pressure, especially if you have other health factors that put you at risk.

Stage 2 hypertension occurs when your readings consistently fall in this range:

  • A top reading of 130–139
  • A bottom reading of 80-89

At this point, you will need to make significant lifestyle changes, take medication, and monitor your blood pressure daily.

If you are experiencing hypertension, your doctor may recommend regular monitoring, which includes taking your blood pressure every 30 minutes to get a realistic average rating for the doctor to assess. Taking regular readings may also help you to take the actions that help you lower your readings long-term.

When should I worry that my blood pressure is dangerously high (or low)?

A hypertensive (blood pressure) crisis happens when your blood pressure spikes super high — around 180/120 mm Hg. If you ever see a reading like this when you are taking your blood pressure at home, immediately take it again to ensure it is not a fluke. And if the reading is the same or similar, consider it an emergency. Contact your doctor, or if you are experiencing other symptoms too, such as chest or back pain, shortness of breath, numbness, weakness, change in vision or difficulty speaking, call 911.

By the way, blood pressure can also drop lower than normal, a condition called hypotension, which is rarer than high blood pressure. It can be accompanied by fainting, dizziness, and other symptoms. While it is not often as dangerous as hypertension, if your blood pressure suddenly drops to 90/60 mm Hg or lower, or if it is accompanied by serious symptoms such as heavy bleeding or shock, seek immediate medical help to find out what is happening and address any issues that could be life-threatening.

Which blood pressure number is more dangerous: systolic or diastolic?

Most often, the top or first number in your blood pressure is what gets the most attention, because it is such a strong indicator that you may be developing cardiovascular disease. This is especially true once you are over 50 years of age, which is when your blood vessels begin to grow stiffer and experience plaque buildup.

But do not overlook the bottom or second number. A consistently high diastolic blood pressure rating can indicate an increasing risk factor for ischemic heart disease and stroke — both of which are serious conditions you should not ignore. These risks increase for people over the age of 40.

What can affect my blood pressure numbers?


As the body ages, its systems begin to wear down. Your arteries are not as flexible as when you were younger, and plaque builds up on the artery walls, making it harder for blood to pass through. This is a main cause of higher blood pressure in those over 50. Since blood pressure tends to rise as our bodies age, it is important to be more aware of your blood pressure, especially as you get older.


In general, men have a slightly higher average blood pressure than women do, anywhere from 4–8 mm Hg or more. And men tend to experience hypertension more often than women, as a rule. But interestingly, women’s blood pressure actually ends up higher on average than men once they reach the age of 60 and over. So, as you age, you should definitely keep an eye on your blood pressure and do what you can to keep it within a normal range.


Many people do not actually realize they have high blood pressure until they experience symptoms or visit the doctor and get an unpleasant surprise. This is likely because lifestyle choices can affect our blood pressure long before they start to create other, more obvious symptoms. Among the things that can affect blood pressure are lack of physical activity, a poor diet, binge drinking, too much salt intake, smoking and obesity. Eating better, exercising, limiting alcohol and other changes can often be effective in lowering blood pressure.


Finally, your family’s unique history and DNA can be a determining factor in how likely you are to develop high blood pressure. If family members have hypertension, let your doctor know.

Why is blood pressure important when it comes to getting surgery?

Because having any type of medical procedure can result in increased blood pressure (due to both the excitement/anxiety of it as well as your body’s need to regulate itself), your medical team will take readings before the surgery to ensure you are in your best condition before the procedure is done. Depending on what your blood pressure is, what other underlying conditions you are affected by, and what type of procedure you are having, you may need to take time and medication to bring your blood pressure to an acceptable reading before the doctor performs your surgery.

Get Answers that Help You Improve Your Wellness

Whether you need some medical guidance on your blood pressure numbers or you are preparing for a procedure in the Tulsa area, our team provides honest answers, caring healthcare planning, and the confidence you need on your journey of wellness.

We take the time to get to know you, understand how you wish to pursue your healthcare choices, and assist you in choosing a care plan that is a perfect fit for you.

Contact us to set up a consultation today. We are here to serve you!

Related Services

No items found.