Skip to main content

Understanding diabetes and the importance of early screening

Updated: June 16, 2025 | 8 minutes to read

Written by: Ashley Lauretta

Colorful illustration of a patient in a doctor’s office with speech bubbles indicating that they’re discussing diabetes causes and treatments, including diet and weight.

About 38 million Americans — or roughly 1 in 10 — are living with diabetes, and 23 percent of them are undiagnosed, according to a 2021 estimate.1 Here’s how to find out who’s at risk.

In this article:

Diabetes, especially when uncontrolled, can result in nerve damage, heart disease, chronic kidney disease, and vision and hearing loss, among other complications.2 The same 2021 study indicates that 1 in 3 U.S. adults have prediabetes,3 its precursor; for those ages 65 and older, it’s nearly 1 in 2.4 Of the approximately 98 million adults considered prediabetic, more than 80 percent are estimated to be unaware of their condition.5

“People with prediabetes and type 2 diabetes can remain asymptomatic for years and, in some cases, develop complications before they get diagnosed and treated effectively,” says Kathleen Dungan, MD, MPH, associate professor of medicine in the Division of Endocrinology, Diabetes and Metabolism at Ohio State University.6 A blood test from a health care provider can identify if someone has type 2 diabetes.7

Understanding diabetes

Be prepared by getting screened now.

What is diabetes?

Diabetes is a chronic disease that affects how the body turns food into energy. Insulin, a hormone made by the pancreas, helps cells to use sugar from the bloodstream.11 When a person has diabetes, their body’s cells don’t respond to insulin properly or their pancreas can’t make enough. Instead of being used as energy by their cells, sugar lingers in the bloodstream, and, over time, this can cause serious health problems.12

What’s the difference between type 1 and type 2 diabetes?

Type 1 diabetes

About 5 to 10 percent of people with diabetes have type 1, and they are usually diagnosed as children, teens or young adults. In type 1 diabetes, the pancreas loses the ability to make enough insulin.13

Type 2 diabetes

About 90 to 95 percent of people who have diabetes have type 2. The onset of type 2 diabetes can be prevented or delayed with healthy lifestyle changes, such as losing weight, eating healthy food and being active.14

Gestational diabetes

Gestational diabetes can occur during pregnancy in those who have never had diabetes. Having gestational diabetes increases the risk of developing type 2 diabetes later in life. Pregnant patients are usually screened for gestational diabetes between 24 and 28 weeks of pregnancy.15

How to help lower the chances of developing type 2 diabetes

Studies have shown that prediabetes is manageable with lifestyle changes, and type 2 diabetes itself can sometimes be controlled with lifestyle changes, with or without medication.16

“Changes in diet and exercise that promote weight loss can make an impact on the risk of developing type 2 diabetes,” says Dr. Dungan. “And you don’t even really need to lose a ton of weight. If you are overweight, just a 5 to 7 percent weight loss was demonstrated in clinical trials to reduce the risk.” A weight-loss program should be conducted under the supervision of a health care provider.17

If a health care provider diagnoses a person with prediabetes, consider it an alert that their body may be on the way to type 2 diabetes. “Think of it as a warning sign,” says Edward Chao, DO, a clinical professor of medicine at the University of California, San Diego. “The good news is that with lifestyle changes, there are a lot of folks who never develop full-blown diabetes.”18

Currently, we don’t know how to prevent type 1 diabetes, but there are steps a person can take to lower their risk of developing type 2 diabetes.19 Losing a small amount of weight if they’re overweight and getting regular physical activity can aid in type 2 diabetes prevention.20

The U.S. Department of Health and Human Services recommends at least 150 minutes per week of moderate-intensity aerobic activity — think cycling, aqua aerobics, power walking or dancing — as well as two to three days of strength training.21 Check with a health care provider before embarking on a new exercise regimen.22

What is the importance of diabetes screening?

Prediabetes is typically asymptomatic, and patients with type 2 diabetes often do not experience many symptoms in the early stages; that’s why it’s important to get tested regularly, especially if someone is considered high risk.23

Dr. Chao explains that diabetes risk factors are connected to age, weight, ethnic background, family history and more.24, 25 (Bear in mind that a person can still develop diabetes even if they are at a healthy weight.26) Find an online prediabetes questionnaire from the Centers for Disease Control and Prevention (CDC) to help better understand the risk for prediabetes.

Staying on top of annual physicals and the requisite blood work will help a health care provider identify if someone has prediabetes. Identifying whether someone has prediabetes early on can help encourage them to make necessary lifestyle changes to help prevent type 2 diabetes.

What are common diabetes symptoms? 

It’s also important to be aware of diabetes symptoms in case they do appear. Common signs of diabetes include:27

  • Blurry vision
  • Fatigue
  • Frequent urination
  • Increased thirst and/or hunger
  • Numb or tingling hands or feet
  • Severely dry skin
  • Sores that are slow to heal
  • Unexplained weight loss

How to test for diabetes

To test for diabetes, a health care provider will likely order one of the following screenings if someone is at risk or shows signs or symptoms of diabetes.28

A fasting glucose test or fasting blood sugar test are two different names for the same diabetes test that measures the blood sugar (or glucose levels) after an overnight fast (not eating).

They may also conduct an oral glucose tolerance test, where the blood sugar is measured before and after consuming a sugary liquid. Lastly, the hemoglobin A1C test measures the average blood sugar levels over the past two to three months.29

Because the A1C test doesn’t require an eight-hour fast, Dr. Chao says that the results remove an element of human error: “Sometimes, patients don’t remember if they’ve fasted or not.”

For fasting blood glucose, a reading of less than 100 milligrams per deciliter (mg/dL) (the glucose found in a set amount of blood) is considered normal; 100 to 125 mg/dL indicates prediabetes; and any reading above 126 mg/dL indicates diabetes.30

The numbers are slightly different for a glucose tolerance test. A blood sugar level of 140 mg/dL or below is normal; 140 to 199 mg/dL indicates prediabetes; and 200 mg/dL or above indicates diabetes when measured two hours after drinking the sugary liquid.31

For an A1C test, a normal result is a level below 5.7 percent; prediabetic is 5.7 to 6.4 percent; and diabetic is 6.5 percent or higher.32, 33

Any of these tests can be used to diagnose diabetes, but a health care provider may use more than one type or repeat the same test before confirming a formal diagnosis.

People with diabetes, prediabetes or a high risk of developing the disease should monitor their A1C or blood glucose with regular testing.34, 35 Talk to a health care provider about the best plan of action. They may recommend laboratory testing and at-home tests as well. Self-administered tests — such as the CVS Health® At Home A1C Test Kit — give results within five minutes. For an in-person screening, talk to a health care provider or visit a MinuteClinic® location that offers A1C testing.36

Glucometers and lancets

Those with a diabetes diagnosis will want to work closely with their health care providers, including their pharmacist, and, if possible, a diabetes educator and nutritionist. “It’s certainly possible to live well with diabetes,” says Dr. Chao. “A plan for diabetes care may include at-home testing as well.”37

People can test with a blood glucose monitor like the OneTouch Ultra2 Diabetes Blood Glucose Monitor, CVS Health Advanced Bluetooth Blood Glucose Meter or CVS Health Premium True Metrix Glucose Meter.

This will give someone a snapshot of their glucose level at the moment of testing, which may be useful for seeing how certain meals affect your level. People with diabetes should take A1C tests for what Dr. Chao calls “the 10,000-foot view” in their doctor’s office at least twice a year. They may also test at home between visits if they wish.

If someone has already been diagnosed with diabetes and is testing their blood sugar levels, they can find glucometer test strips and lancets on CVS.com® as well.

Test strips

Lancing devices and lancets

In conclusion, don’t be afraid to learn about blood sugar status to help prevent serious complications down the road. As Dr. Chao says, “I believe increasing awareness and decreasing stigma is so important — so this disease doesn’t sneak up on you.”

This content is for informational purposes only and is not intended to replace professional medical advice, diagnosis or treatment. Consult your health care provider if you have any questions about medications, vitamins or supplements you may be considering or changes to your wellness or health care routines.

You may also like

Explore more topics

Browse all topics