What Is Diabetes?

Diabetes is taking a serious toll on our nation. About 38 million Americans suffer from the life-threatening disease — and the numbers keep growing. With diabetes, the body can no longer make enough insulin or use the insulin it does make to control blood sugar (blood glucose).

Most people living with diabetes (about 95 percent), have Type 2 diabetes. With Type 2, the body makes insulin, but doesn’t respond to insulin the way it should. The other five percent have Type 1 diabetes, which keeps the body from making insulin. In both conditions, your body loses its typical ability to keep bloodstream levels of glucose (sugar) within safe limits. This leads to chronically high levels of glucose, known as hyperglycemia.  

The Dangers of Diabetes

About one in five people with diabetes don’t even know they have the disease. Ignoring your risk for diabetes is dangerous because it can damage your internal organs.

High blood sugar, or hyperglycemia, increases inflammation in your arteries. When this happens, your organs don’t get the blood they need to stay healthy and function properly. This increases your risk for stroke, heart attack, kidney failure, vision loss and advanced memory loss.

Diabetes also makes it difficult for wounds to heal. In some cases, poor circulation can lead to gangrene and even amputation of extremities.

Know These Warning Signs

Diabetes doesn’t always give a clear warning. Signs may be mild or go unnoticed. Watch for these common symptoms:

• Urinating often
• Feeling more thirsty than usual
• Feeling moody or irritable
• Feeling really hungry 
• Losing weight (Type 1)
• Gaining weight (Type 2)
• Feeling weak
• Feeling tired
• Tingling or numbness in hands or feet
• Wounds that don’t heal
• Gum or bladder infections
• Having blurry vision

Diagnosing Diabetes

Simple blood tests can offer answers. For a fasting blood sugar test, a sample of blood is taken the morning after an overnight fast to measure the body’s blood sugar level.

• Less than 100 milligrams per deciliter (mg/dL) is considered normal
• 100 to 125 mg/dL is considered insulin resistant or prediabetes
• 126 mg/dL or higher on two separate tests is considered diabetes

More often, blood is drawn for a hemoglobin A1C test to measure the body’s blood sugar level over the past two to three months. You do not need to fast for this blood test.

• Normal – less than 5.7%
• Prediabetes (insulin resistance) – 5.7% to 6.4%
• Diabetes – 6.5% or higher

Once you have diabetes, even if you get it under control with insulin or medication, you will still have to deal with its long-term effects on your organs. Even if you don't require medication, you will always be considered a person living with diabetes.

Keep Diabetes at Bay

Insulin resistance offers a small window for a course correction. By making these healthy changes, many people who are insulin resistant can return their blood glucose levels to normal ranges and prevent insulin resistance from becoming Type 2 diabetes. In other words, healthier habits can help lower your risk of developing diabetes. Here’s how.

Lose the extra pounds. Type 2 diabetes is often driven by excess weight, so losing it can improve your health. While weight loss can seem daunting, studies show that even a modest weight loss of just 7 to 10 percent of your body weight — combined with regular exercise—can reduce the risk of developing diabetes by nearly 60 percent.

Get moving and keep moving. There are so many good reasons to exercise. Besides helping you maintain a healthy weight, physical activity lowers your blood sugar and boosts your sensitivity to insulin.  This helps keep your blood sugar within a normal range.

Eat good food. In a time when frozen and fast foods make it far too easy to choose convenience over nutrition, we’ve moved away from what our bodies really want and need — fresh, healthy foods that aren’t loaded with hidden sugars and fats.

Talk with your doctor. Be proactive and schedule your annual physical exam. Ask your doctor if you should be screened for diabetes and discuss steps you can take to prevent it.

Find more in-depth information about diabetes monitoring and treatment in our series of easy-to-understand videos.

Diabetes Videos: 

• Learn about the importance of checking your blood sugar when using insulin. 
• Learn about insulin injections. 
• Learn about injecting insulin with a pen. 
• Learn about the importance of filling your prescription. 
• Learn about your A1C. 

Sources: Diabetes Basics,  The Centers for Disease Control and Prevention, 2024; Blood Glucose and Insulin,  Prediabetes,  American Diabetes Association

Originally published 1/13/2016; Revised 2019, 2022, 2024