A new Cleveland Clinic study revealed that Americans don't know much about risk factors that could prevent heart disease.

You probably think you know your body well — every callus, patch of freckles and roll of flab. Then there are the more important things: the stuff on the inside like your blood pressure and cholesterol. But if someone asked for your body mass index, would you be able to tell them?

One in four Americans dies from heart disease every year. It is actually the No. 1 killer in the U.S. and across the globe. Yet a recent study found that most of us don’t even know our bodies’ basic stats — knowledge which could save our lives.

Cleveland Clinic researchers tested Americans on their knowledge of body mass index, blood pressure, cholesterol, waist circumference, glucose and weight in a recent survey. Sounds like easy stuff, right? Wrong. They found that while 68 percent of Americans worry about dying from heart disease, only 38 percent knew their blood pressure, and a mere 18 percent knew their BMI.

Even fewer people could identify the healthy ranges for these health factors. For example, less than 50 percent of Americans surveyed knew that a healthy blood pressure rating is 120/80, and less than a quarter (23 percent) knew that someone is considered overweight when they have a BMI of 25 or more.

You might be wondering why it even matters whether you know your body’s stats or not. Well, according to Steve Nissen, M.D., chairman of cardiovascular medicine at Cleveland Clinic, knowing these numbers could save your life.

“Studies have suggested the majority of coronary artery disease events can be prevented by addressing treatable risk factors,” he says in a press release.

“Although there are some definitive factors, there are others that can be modified. You can modify your blood pressure, you can modify your blood sugar, you can modify your weight, and very often you can modify your cholesterol levels,” Leonardo Rodriguez, M.D., cardiologist and director of the Advanced Imaging Training Program at the Cleveland Clinic, tells LIVESTRONG.COM. “If you are a young person but you have family history [of heart disease], it’s important to begin early in life to try to modify your risk factors in order to prolong your life and reduce the dire consequences of heart disease like stroke and heart attack.”

To gather their information, Cleveland Clinic researchers conducted phone interviews of 1,002 adults in the continental United States.

Here are a few more findings that will make you worry about everyone you know:

Good Cholesterol, Bad Cholesterol

Health vocab isn’t America’s strong suit. Most of the people surveyed think that triglycerides are cholesterol, when actually they’re a type of fat in the blood. Also, only one in four Americans said that HDL is the “good” kind of cholesterol, and about half (52 percent) knew that your LDL cholesterol is an important number to know when it comes to understanding your risk of heart disease.

Shape Matters?

Did you know that your fat in the stomach region is the most dangerous factor for heart health? If you said no, you’d be part of the two-thirds of Americans who also don’t know. About a third of people surveyed knew that waist circumference is even important when it comes to determining risk of heart disease.

Taking Our Vitamins

First, there’s little evidence that supplements enhance heart health. Yet nearly seven in 10 (67 percent) people said that they’ve taken one or more supplements regularly to improve their heart health.

What’s Diabetes Got to Do With It?

Most participants (73 percent) didn’t know that the leading cause of death for people with diabetes is heart disease. In fact, the most common response (35 percent) was kidney disease/failure.

What You Need to Know

The healthy ranges for your body’s stats are:

  • Blood pressure — less than 140/90 mm Hg
  • Fasting blood sugar — less than 100 mg/dL
  • LDL, or “bad,” cholesterol — about 100 mg/dL
  • BMI — 25 or less
  • Waist circumference — about 31.5 inches for the average-sized women and 37 inches for average-sized man

Check on these bad boys at least once a year. “It’s important to have an open communication with your doctor and ask them, ‘What’s my blood pressure today? Have you ever checked or will you check my blood sugar and cholesterol?’” Rodriguez says.

And you probably guessed the best ways to improve your risk factors: eating a healthy diet and exercising! Try to keep your meals full of veggies, and choose the stairs over the elevator. Exercise three times a week when you can, and go for walks during your work breaks.

For more info on American heart health, visit cle.clinic/loveyourheart.

What Do YOU Think?

Do you know your blood pressure, blood sugar, BMI, bad cholesterol and waist circumference? Does your doctor usually tell you your numbers when you go in for a checkup? What are your favorite ways to incorporate exercise into your day? Let us know in the comments section!