Diabetes is a dysfunction of the body's sugar metabolism, which causes sugar to build up in the blood. During digestion this "anomaly" causes food being broken down into small molecules, especially glucose (sugar), that passes into the bloodstream and then increases blood glucose. At this signal, the pancreas secretes a hormone, insulin, which will allow the use of sugar by cells for immediate energy needs or for storage in the reserves of the body. The blood glucose then returns to a normal level. In the case of diabetes, the pancreas secretes insufficient or no insulin (Type 1 diabetes) or insulin does not function properly (Type 2 diabetes) causing an inappropriate action in the tissues (liver or muscles). This is "insulin resistance". The sugar accumulates in the blood and causes hyperglycemia.