Insulin-dependent diabetes mellitus (IDDM) is a medical term that describes diabetes mellitus that requires insulin therapy

Insulin therapy

Insulin therapy is the treatment of diabetes by administration of exogenous insulin.Insulin is used medically to treat some forms of diabetes mellitus. Patients with Type 1 diabetes mellitus depend on external insulin for their survival because the hormone is no longer produced internally...

 to avoid ketoacidosis

Diabetic ketoacidosis

Diabetic ketoacidosis is a potentially life-threatening complication in patients with diabetes mellitus. It happens predominantly in those with type 1 diabetes, but it can occur in those with type 2 diabetes under certain circumstances...

. IDDM is often considered a synonym for juvenile diabetes mellitus and type 1 diabetes mellitus, though the three terms are not entirely congruent:

• Juvenile diabetes is considered an unsatisfactory and somewhat obsolete term because type 1 diabetes can develop in adults, and type 2 can occur in children.
• IDDM includes type 1 diabetes, but as type 2 diabetes progresses, in some people it may reach a degree of insulin
  Insulin
  Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
  
   deficiency that requires insulin treatment.

See diabetes mellitus

Diabetes mellitus

Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

, type 1 diabetes mellitus, and type 2 diabetes mellitus.