What Blood Pressure, A1C, BMI, and Cholesterol Really TellYou
When you visit your primary care provider for an annual checkup, you may hear a lot of numbers. Your blood pressure might be 118/76. Your A1C may be 5.7%. Your cholesterol may have several numbers listed on your lab report.
But what do those numbers actually mean?
Your healthcare provider looks at these measurements to get a better understanding of your health and identify potential concerns. Knowing what they measure can also help you have more informed conversations with your provider about your health.
Here’s a closer look at four common health measurements, plus how pediatricians track growth and development in children:
1. Blood Pressure
Blood pressure measures the force of your blood pushing against the walls of your blood vessels as your heart pumps blood throughout your body.
A blood pressure reading has two numbers. The systolic number, or the top number, measures the pressure in your arteries when your heart beats. The diastolic number, or the bottom number, measures the pressure between heartbeats, when your heart is resting.
You may have heard that 120/80 mm Hg is a “normal” blood pressure reading. However, blood pressure categories are based on ranges, and a single reading does not necessarily tell the whole story. Your provider will consider your readings over time, along with your overall health and other risk factors.
High blood pressure often does not cause noticeable symptoms, which is one reason regular checkups are important. Over time, uncontrolled high blood pressure can increase your risk of heart disease, stroke, kidney disease, and other health problems.
Your provider may recommend lifestyle changes, medication, or a combination of both depending on your blood pressure and individual health needs.
2. A1C
An A1C test measures your average blood sugar levels over approximately the past two to three months. Unlike a blood glucose test, which measures your blood sugar at a specific point in time, an A1C gives your provider a longer-term look at how your blood sugar has been running.
A higher A1C can indicate that your blood sugar levels have been higher than recommended. Depending on the result, your provider may use the test to identify prediabetes or diabetes, or to monitor diabetes that has already been diagnosed.
For many adults:
- An A1C below 5.7% is considered in the normal range.
- An A1C of 5.7% to 6.4% falls in the prediabetes range.
- An A1C of 6.5% or higher may indicate diabetes and typically requires confirmation with repeat testing or another diabetes test.
Your individual target may be different if you have diabetes or another health condition, so talk with your provider about what your number means for you.
Healthy eating habits, regular physical activity, and taking medications as prescribed, when medications are needed; can all play a role in managing blood sugar.
3. BMI
BMI, or body mass index, is a calculation based on your height and weight. Healthcare providers may use it as one tool when evaluating weight-related health risks.
For adults, BMI categories are generally:
- Below 18.5: Underweight
- 18.5 to 24.9: Healthy weight
- 25 to 29.9: Overweight
- 30 or higher: Obesity
BMI can be useful, but it does not tell your provider everything about your health. It does not directly measure body fat, and it does not account for factors such as muscle mass, body composition, or where fat is distributed throughout the body.
That’s why your provider should look at BMI alongside other information, such as your blood pressure, cholesterol, blood sugar, medical history, family history, lifestyle, and overall health.
If your provider has concerns about your weight or weight-related health risks, they can work with you to determine what steps, if any, make sense for you.
4. Cholesterol
Cholesterol is a waxy substance your body needs to build cells and make certain hormones and vitamins. Your liver makes cholesterol, and you also get some cholesterol from foods that contain it.
Because cholesterol does not travel through your bloodstream on its own, it is carried by proteins called lipoproteins. Your cholesterol test typically includes several measurements, including LDL and HDL cholesterol.
LDL cholesterol is often called “bad cholesterol.” Too much LDL can contribute to plaque buildup in the arteries, which can increase the risk of heart attack and stroke.
HDL cholesterol is often called “good cholesterol” because it helps transport cholesterol back to the liver. However, cholesterol health is more complicated than simply having a high HDL number. Your provider will consider your full cholesterol panel, along with your other health
information and risk factors.
Your cholesterol levels can be influenced by genetics, diet, physical activity, certain health conditions, and medications. Depending on your individual risk factors and cholesterol levels, your provider may recommend lifestyle changes, medication, or both.
What About Children’s Health Numbers?
Children aren’t simply “little adults,” and their health numbers should not be interpreted the same way as adults’ numbers. Lab values and health measurements can mean different things depending on a child’s age and stage of development. A result considered abnormal for an adult may be normal for a child, and vice versa.
That’s why it’s important to ask your child’s healthcare provider about age-appropriate reference ranges rather than applying adult ranges to children. Your pediatrician can explain what a lab result or measurement means in the context of your child’s age, growth, development, and overall health.
Instead of using adult BMI categories or focusing on the same numbers used for adults, pediatricians track children’s growth and development over time.
One of the primary tools they use is a growth chart. Growth charts help providers see how a child’s height or length, weight, and, for younger children, head circumference compare with other children of the same age and sex.
Growth charts use percentiles to show where a child’s measurements fall within the reference population.
For example, if a child’s height is at the 60th percentile, that means about 60% of children in the reference group are shorter, while about 40% are taller.
A percentile is not a grade, a score, or a measure of how healthy a child is. A child can be healthy at a wide range of percentiles.
What matters most is often the pattern of growth over time. If a child’s growth changes significantly or does not follow the expected pattern, a pediatrician may look more closely at the child’s nutrition, development, medical history, and other factors.
Parents should not try to interpret a single measurement, lab result, or percentile on their own.
Your child’s pediatrician can explain what the numbers mean using the appropriate reference ranges and in the context of your child’s overall health and development.
Your Numbers Are Only Part of the Picture
Your health cannot be summed up by a handful of numbers.
Blood pressure, A1C, BMI, cholesterol, and other measurements give your primary care provider useful information, but they are only part of a much bigger picture. Your age, medical history, family history, medications, lifestyle, symptoms, and other factors all help your provider understand what your numbers mean for you.
If you have questions about a number on your lab report or during a checkup, ask your doctor to clarify it for you. Understanding your health information can help you take a more active role in your care.
Whether you need a routine checkup, help managing an ongoing health concern, or care for your child’s growth and development, we offer primary care and pediatric services for patients and families.