Diabetes is a group of diseases characterized by high blood sugar. When a person has diabetes, the body either does not make enough insulin or is unable to use its own insulin well. If blood sugar builds up in the body and its levels are not controlled, it can lead to serious health complications, such as heart disease, stroke, kidney disease, blindness, amputations of the legs and feet, and early death. CDC programs and other scientific activities support improvements in health outcomes for people with type 1 diabetes, type 2 diabetes, gestational diabetes, and prediabetes.

Take the risk test
National Diabetes Prevention Program

Introduction to Diabetes


People without diabetes have normal blood glucose levels

If you don’t have diabetes, your food is digested in your stomach and changed into glucose (a kind of sugar). The glucose travels in your bloodstream to your body cells. Insulin produced by your pancreas allows the glucose to enter your body cells and gives them energy.

People with diabetes have blood glucose levels that are too high

Your pancreas is not making enough insulin, or the insulin it makes does not work well. Either way, without insulin your cells can’t get the glucose they need. Instead, the glucose builds up in your bloodstream, so the cells 'starve' while the glucose level in the blood rises.

When your blood glucose level gets very high, your body gets rid of the glucose and calories through your urine. As a result, you may have one or more of the following signs:
  • Thirst 
  • Urinating more than usual 
  • Feeling very hungry 
  • Losing weight without trying 
  • Feeling more tired than usual 
  • Sores that heal slowly 
  • Dry, itchy skin 
  • Losing feeling in your feet, tingling in hands and feet 
  • Sexual dysfunction 
  • Blurry eyesight

Diabetes is a chronic disease

Diabetes is a chronic disease. It does not go away, even with treatment. It is also progressive, meaning that if left untreated, it can lead to difficult complications. The good news is that diabetes can be controlled. However, it must be carefully monitored to keep it in control.

A treatment plan that works at first may need to be adjusted as time passes to keep your blood glucose in its “target range”, where it should be most of the time. Your health care team will work with you to decide the blood glucose target ranges that are right for you.

Learn more about the different types of diabetes:
Type 1 diabetes
Type 2 diabetes
Gestational diabetes
Other types of diabetes 

Other Types of Diabetes-

Other types of diabetes include maturity-onset diabetes of the young or latent autoimmune diabetes in adults. These types of diabetes are caused by specific genetic conditions or from surgery, medications, infections, pancreatic disease, or other illnesses. Other types of diabetes account for 1%-5% of all diagnosed cases.


People with prediabetes have blood sugar levels that are higher than normal, but not high enough to be considered diabetes. Prediabetes can put people at increased risk of developing type 2 diabetes, heart disease, and stroke.