CSP: subtype of diabetes mellitus that is characterized by insulin deficiency; it is manifested by the sudden onset of severe hyperglycemia, rapid progression to diabetic ketoacidosis, and death unless treated with insulin; the disease may occur at any age, but is most common in childhood or adolescence.,NCI: Diabetes mellitus characterized by insulin deficiency, sudden onset, severe hyperglycemia, rapid progression to ketoacidosis, and death unless treated with insulin. The disease may occur at any age, but is most common in childhood or adolescence.,MEDLINEPLUS: Diabetes means your blood glucose, or blood sugar, is too high. With Type 1 diabetes, your pancreas does not make insulin. Insulin is a hormone that helps glucose get into your cells to give them energy. Without insulin, too much glucose stays in your blood. Over time, high blood glucose can lead to serious proble