Type 1 diabetes is a chronic condition in which the pancreas makes little or no insulin. Insulin is a hormone that helps blood sugar enter the cells in the body for use as energy. Without insulin, blood sugar builds up in the bloodstream, which can cause serious complications. Type 1 diabetes was once called insulin-dependent or juvenile diabetes, but it can develop at any age. It is less common than type 2 diabetes, with only about 5-10% of people with diabetes having type 1.

The exact cause of type 1 diabetes is unknown, but experts think it is caused by genes and factors in the environment, such as viruses, that might trigger the disease. Some people have certain genes that make them more likely to develop type 1 diabetes, but many of them won’t go on to have type 1 diabetes even if they have the genes. Symptoms of type 1 diabetes can appear suddenly and may include increased thirst and urination, increased hunger, blurred vision, and weight loss without trying.

Diagnosis of type 1 diabetes involves checking blood sugar levels and testing urine for glucose or chemicals called ketones. Health care professionals most often use the random plasma glucose (RPG) test to diagnose type 1 diabetes. Treatment for type 1 diabetes is directed toward managing the amount of sugar in the blood using insulin, diet, and lifestyle to prevent complications. There is currently no cure for type 1 diabetes.