Final answer:
When blood sugar is uncontrolled, it can lead to diabetes mellitus and various disorders such as ketoacidosis, heart attacks, strokes, blindness, and kidney failure.
Step-by-step explanation:
When blood sugar isn't controlled, it can lead to a condition called diabetes mellitus, which is characterized by dysfunction of insulin production and secretion as well as the target cells' responsiveness to insulin. There are two major types of diabetes: type 1 and type 2. Poorly controlled blood sugar levels in diabetes can cause various disorders such as ketoacidosis (increased blood acidity), heart attacks, strokes, blindness, and kidney failure, among others.