Cause

Type 1 diabetes develops because the body's immune system destroys the beta cells which are in the islet tissue in the pancreas. These beta cells produce insulin. So people with type 1 diabetes cannot make their own insulin.

You can inherit a tendency to develop type 1 diabetes, but most people who have the disease have no family history of it. Diabetes experts believe that a genetic tendency and some environmental factors may increase the risk of developing type 1 diabetes. Possible environmental factors include enteroviral infections—especially Coxsackie B infections.

Despite concerns about vaccines (particularly those against whooping cough and Haemophilus influenzae type b, or Hib), studies have not found a relationship between being vaccinated and developing type 1 diabetes.¹

Symptoms

Symptoms of type 1 diabetes usually develop quickly, over a few days to weeks, and are caused by blood sugar levels rising above the normal range (hyperglycemia). Early symptoms may be overlooked, especially if the person has recently had an illness, such as influenza (flu). Early symptoms include:

• Frequent urination, which may be more noticeable at night. Some young children who have learned to use the toilet may start wetting the bed during naps or at night.
• Extreme thirst and a dry mouth.
• Weight loss.
• Increased hunger (possibly).

Sometimes the blood sugar level rises excessively before a person knows something is wrong. Because insulin is not available, the cells in the body are unable to get the sugar (glucose) they need for energy. The body begins to break down fat and muscle for energy. When fat is used for energy, ketones—or fatty acids—are produced and enter the bloodstream, causing the chemical imbalance diabetic ketoacidosis. This is a life-threatening condition. Symptoms of diabetic ketoacidosis are:

• Flushed, hot, dry skin.
• Loss of appetite, abdominal pain, and vomiting.
• A strong, fruity breath odor.
• Rapid, deep breathing.
• Restlessness, drowsiness, difficulty waking up, confusion, or coma. Young children may lack interest in their normal activities.