Blood pressure and cholesterol: The truth behind the numbers
Your age, your height, your body mass index, your heart rate—there are many ways your health is measured in numbers.
Most of the time, these numbers are straightforward. You know what they are, and you know what they mean. Other times, they're more complex, like when it comes to your blood pressure and cholesterol.
What are blood pressure and cholesterol?
- Blood pressure is the pressure of your blood against the walls of your arteries, which carry blood from your heart to the rest of your body.
- Cholesterol is a waxy substance that travels in your blood and is used to make cells, vitamins and hormones.
While blood pressure and cholesterol are different things, they are connected. For starters, high cholesterol can cause high blood pressure. What's more, either of them can cause heart disease—the leading cause of death for both men and women in the United States.
Michael L. Tobin, MD, a cardiologist at Lankenau Heart Institute, part of Main Line Health, uses these numbers day in and day out. They help him understand how healthy his patients' hearts are and determine how to care for them moving forward.
While Dr. Tobin may rely on blood pressure and cholesterol numbers to do his job, you're not alone if these numbers are a little (or a lot) confusing.
Here are 5 truths to help you understand more about your blood pressure and cholesterol.
1. High blood pressure is always a concern
High blood pressure (also known as hypertension) is when your blood pressure numbers are higher than normal. To measure your blood pressure, your provider uses two numbers:
- Systolic blood pressure, which is the pressure in your arteries when your heart beats
- Diastolic blood pressure, which is the pressure in your arteries when your heart rests
Normal blood pressure is less than 120 systolic and 80 diastolic. This is written as 120/80 mmHg and read as "120 over 80."
If your blood pressure is higher than 120/80, that's considered high blood pressure—something that always is a concern.
"Blood pressure that's high is always going to be bad," explains Dr. Tobin. "You can always say, 'This blood pressure is bad, and if we lower it, that's good,'" he says.
This is because, over time, high blood pressure can cause damage to your arteries, decreasing the flow of blood and oxygen to your heart and other organs (like your brain or kidneys). Eventually, high blood pressure can lead to problems like kidney disease, heart attack or stroke.
Fortunately, there are ways to lower your blood pressure, such as lifestyle changes (like adjusting your diet or exercise routine) or medications.
2. ...but high cholesterol is a little more complicated.
Cholesterol is less straightforward than blood pressure. This is partly because not all cholesterol is bad. Good cholesterol is known as high-density lipoprotein (HDL), while bad cholesterol is known as low-density lipoprotein (LDL).
In general, ideal cholesterol levels are:
- Lower than 200 mg/dL (total cholesterol)
- Lower than 130 mg/dL (LDL)
- Higher than 40 mg/dL for men, and 50 mg/dL for women (HDL)
However, your target numbers can vary quite a bit depending on your age, other health conditions and which kind of cholesterol is high. For instance, if your total cholesterol level is high because of a high LDL level, that can put you at risk of heart disease or stroke. But if your total cholesterol level is high because of a high HDL level, you may not be at a higher risk.
For Dr. Tobin, your heart health is about much more than just your cholesterol numbers.
"Where we want cholesterol to be will vary depending on what else the patient has going on," says Dr. Tobin. "Cholesterol is better thought of as someone's overall risk assessment—the likelihood of them developing what we call ASCD, or atherosclerotic cardiovascular disease. This is what puts people at risk for things like heart attack and stroke."
But, as Dr. Tobin explains, high cholesterol doesn't necessarily mean you'll develop cardiovascular disease. On the other hand, you can still have cardiovascular disease without high cholesterol.
"Cholesterol is a part of the picture—not a direct link," he explains.
3. Black Americans have a higher risk of developing high blood pressure—and a higher risk of complications.
The rate of high blood pressure among Black Americans is one of the highest in the world, with over 50% of the population having the condition.
What's more, their risk of complications is also higher. "There is a lot of data and research showing that Black Americans have more complications related to high blood pressure, like kidney disease and stroke, than white Americans," says Dr. Tobin. This may be due to any number of factors, such as lack of access to care and medication as well as distrust of medical professionals due to a history of discrimination.
Some blood pressure medications may also not be as effective in controlling blood pressure in Black people, likely because of other health conditions and their side effects.
"When we're choosing what blood pressure medicines to start a patient on, we're really choosing the medicine based on the side effects of that medicine," Dr. Tobin explains. "We always try to pick medicines that, in addition to treating high blood pressure, also do good things. We'll also avoid medicines that would be specifically bad for that group of patients."
Keep in mind—higher risk for high blood pressure doesn't necessarily mean high blood pressure is inevitable. And if you do develop high blood pressure, early detection can go a long way, especially among more vulnerable populations.
As Dr. Tobin says, "It's important to be aware of your risk and make sure you're being vigilant about monitoring blood pressure."
4. Your blood pressure varies a lot throughout the day, including at your healthcare provider's office.
You may have noticed that each time you have your blood pressure taken, it's a different set of numbers. This is completely normal. Your blood pressure changes throughout the day depending on the time of day, what you're doing and how you're feeling.
"Everyone's blood pressure is going to go up sometimes, like when they're walking up the stairs or if they're in pain," says Dr. Tobin.
Increased blood pressure can also occur at your healthcare provider's office. This is called white-coat hypertension—when your blood pressure rises due to anxieties of being in your provider's office. "White-coat hypertension is more common than we probably think it is," he says.
Rather than focusing on a one-time blood pressure reading, Dr. Tobin looks for a trend. He'll start by reviewing your blood pressure history. And if you take your blood pressure at home (something Dr. Tobin recommends for all patients with high blood pressure), he'll compare those numbers to what he's getting in his office.
5. Genetic testing for high cholesterol can be helpful—to an extent.
Your parents may have given you your eye color or your sense of humor, but they may also have given you high cholesterol.
Familial hypercholesterolemia (FH) is a genetic condition that keeps your body from recycling bad cholesterol (LDL). This leaves you with high LDL levels and a higher risk for other health conditions.
With FH, you're basically born with high cholesterol. This means that you're getting the negative effects of high cholesterol for a long time. Men with FH can develop coronary heart disease up to 20 years earlier and women can develop it up to 30 years earlier.
As a result, genetic testing for FH can be helpful. However, it's just one piece of the puzzle.
"In most cases, you're able to diagnose patients based on high cholesterol," explains Dr. Tobin. "And if you're screening for those high cholesterol levels, getting that person on appropriate therapy is straightforward enough."
However, there are some cholesterol subtypes that aren't measured in a routine blood test. For example, lipoprotein A, which is a risk factor for cardiovascular disease, can be associated with familial hypercholesterolemia. If Dr. Tobin suspects you might have a family history of high cholesterol, he may use genetic screening to gather more information.
Understanding your blood pressure and cholesterol numbers starts with your healthcare provider
Your blood pressure and cholesterol numbers are an important part of your overall health. Fortunately, it's not up to you to understand what they mean on your own.
Along with your other risk factors and health data, your healthcare provider will help determine what kind of risk you have for certain conditions, including cardiovascular disease. Together, you can make a plan to keep your heart and body healthy for life.