University of Illinois Extension

Are there different types of diabetes?

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There are three main types of diabetes: type 1 diabetes, type 2 diabetes, and gestational diabetes.

Type 1 Diabetes

Type 1 diabetes can occur at any age, but is most often diagnosed early in life. Type 1 diabetes is called an autoimmune disease, because the immune system attacks the person’s own cells. In this type of diabetes, cells in the pancreas that produce insulin are the target of the body's immune system and are eventually destroyed. For this reason, people with type 1 diabetes produce no insulin so glucose cannot get into the cells.

Symptoms of type 1 diabetes include:

Type 2 Diabetes

Type 2 diabetes is the most common form of diabetes. Ninety-five percent of the people who have diabetes have type 2. Although it was once thought that type 2 diabetes occurred only in adults, it is now known that people can develop type 2 diabetes at any age. With type 2 diabetes, the receptors on the cells become resistant to insulin and therefore cannot let glucose into the cell. Type 2 diabetes may also result if the body does not make enough insulin. Both problems with the cell receptor or with the amount of insulin produced, lead to high blood glucose levels. Being overweight and inactive increases the chance of developing type 2 diabetes.

Insulin resistance is a condition when normal insulin levels do not result in glucose entry into the cell. Higher than normal insulin levels in the blood occur in insulin resistance.

People who have insulin resistance are usually overweight or obese. They may have a normal blood glucose, be diagnosed as “pre-diabetes”, or have type 2 diabetes. People who have a normal blood glucose may have no symptoms of insulin resistance but usually develop pre-diabetes. Those with pre-diabetes usually develop type 2 diabetes. The exception to this progression occurs when overweight or obese people lose weight, eat a healthy diet, and exercise regularly.

Not everyone who is obese or overweight will develop insulin resistance, although a lot of people will. Genetics, diet, and activity levels all can play an important role in how well insulin and glucose interact.

Symptoms of type 2 diabetes include:

  • Frequent urination (polyuria)
  • Thirst (polydipsia)
  • Blurred vision
  • Unintentional weight gain or weight loss, although little weight change may occur
  • Fatigue
  • Many people have no noticeable symptoms

Gestational Diabetes

Gestational diabetes is a form of diabetes that occurs during pregnancy. When a woman becomes pregnant there are many hormonal changes that take place. These changes, especially in the later stages of pregnancy, can affect the mother’s sensitivity to insulin. When the mother becomes resistant to insulin, her cells do not let glucose in and her blood glucose levels rise. When blood glucose levels rise above a certain level, gestational diabetes is diagnosed. Doctors often check women’s blood glucose levels during their pregnancy because high blood glucose levels can cause complications during the pregnancy or after the baby is born. These complications include infants of high birth weight, increased risk of cesarean delivery, infant respiratory distress syndrome, infant hypoglycemia following delivery, and infant jaundice. The presence of fasting hyperglycemia greater than 105mg/dl may be associated with increased risk of fetal malformations and death. Although gestational diabetes usually goes away after the baby’s birth, women with this type of diabetes are at high risk for developing type 2 diabetes later in life.

Back to: General Overview of Diabetes and Food

This document is a source of information only, and is not medical advice.