What is Diabetes? Symptoms and Causes

Article | October 2019

What is Diabetes? Symptoms and Causes

Learn about what causes diabetes, the different types of diabetes, as well as main symptoms and treatments.

What is diabetes?

  • Diabetes is a chronic disease that affects how your body turns food into energy. Most of the food you eat is broken down into sugar (also called glucose) and released into your bloodstream. Your pancreas makes a hormone called insulin, which acts like a key to let the blood sugar into your body’s cells for use as energy.
  • If you have diabetes, your body either doesn’t make enough insulin, or can’t use the insulin it makes as well as it should.
  • When there isn’t enough insulin, too much blood sugar stays in your bloodstream, which over time can cause serious health problems, such as heart disease, vision loss, and kidney disease.

Population Facts:

  • More than 30 million people in the U.S. have diabetes, and 1 in 4 of them don’t know they have it.
  • More than 84 million U.S. adults—over a third—have prediabetes, and 90% of them don’t know they have it.
  • Diabetes is the seventh leading cause of death in the United States (and may be underreported).
  • In the last 20 years, the number of adults diagnosed with diabetes has more than tripled as the American population has aged and become more overweight or obese.

What are the types of diabetes?

There are 3 main types of diabetes: type 1, type 2, and gestational diabetes (diabetes while pregnant).

  • Type 1 diabetes

    About 5 percent of people with diabetes have type 1. It’s caused by an autoimmune reaction (the body attacks itself by mistake) that stops your body from making insulin. It’s usually diagnosed in children, teens, and young adults. If you have type 1 diabetes, you’ll need to take insulin every day to survive. Currently, no one knows how to prevent type 1 diabetes.

  • Type 2 diabetes

    Most people with diabetes—9 in 10—have type 2 diabetes. Your body doesn’t use insulin well and is unable to keep blood sugar at normal levels. It develops over many years and is usually diagnosed in adults (though increasingly in children, teens, and young adults).You may not notice any symptoms, so it’s important to get your blood sugar tested if you’re at risk. Type 2 diabetes can be prevented or delayed with healthy lifestyle changes, such as losing weight if you’re overweight, healthy eating, and getting regular physical activity.

Causes of type 2 diabetes:

Type 2 diabetes develops when the body becomes resistant to insulin or when the pancreas stops producing enough insulin. Genetics and environmental factors, such as excess weight and inactivity, seem to be contributing factors.

You can get type 2 diabetes if:

  • Your body doesn't respond as it should to insulin. This makes it hard for your cells to get sugar from the blood for energy. This is called insulin resistance.
  • Your pancreas doesn't make enough insulin.

If you are overweight, get little or no exercise, or have type 2 diabetes in your family, you are more likely to have problems with the way insulin works in your body. Type 2 diabetes can be prevented or delayed with a healthy lifestyle, including staying at a healthy weight, making healthy food choices, and getting regular exercise.

What are the symptoms of diabetes?

The following diabetes symptoms are typical. However, some people with type 2 diabetes have symptoms so mild that they go unnoticed.

Common symptoms of diabetes include:

  • Urinating often
  • Feeling very thirsty
  • Feeling very hungry—even though you are eating
  • Extreme fatigue
  • Blurry vision
  • Cuts or bruises that are slow to heal
  • Weight loss—even though you are eating more (type 1)
  • Tingling, pain, or numbness in the hands or feet (type 2)

How is type 2 diabetes diagnosed?

The American Diabetes Association recommends routine screening for type 2 diabetes beginning at age 45, especially if you're overweight. If the results are normal, repeat the test every 3 years. If the results are borderline, ask your doctor when to come back for another test.

To diagnose type 2 diabetes, you'll be given a Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past 2 to 3 months. It measures the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached.

What is the treatment for type 2 diabetes?

The key to treating type 2 diabetes is to keep blood sugar levels controlled and in your target range.

To lower your blood sugar:

  • Make healthy food choices. Try to manage the amount of carbohydrates you eat by spreading them out over the day.
  • Lose weight, if you are overweight.
  • Get regular exercise.
  • Take medicines, if you need them.

It's also important to:

  • See your doctor. Regular checkups are important to monitor your health.
  • Test your blood sugar levels. You have a better chance of keeping your blood sugar in your target range if you know what your levels are from day to day.
  • Keep high blood pressure and high cholesterol under control. This can help you lower your risk of heart and large blood vessel disease.
  • Quit smoking. This can help you reduce your risk of heart disease and stroke.

More Information

For more about diabetes, visit the American Diabetes Association website.

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