Diabetes is a condition in which the body fails to respond to insulin properly.
Insulin is the hormone that regulates blood sugar levels. When blood sugar levels are high, the pancreas will make more insulin and release it so that cells are able to receive blood sugar. This is why insulin is often called the key which unlocks cells. When cells reach sugar capacity, insulin helps store the remaining sugar in the liver. When blood sugar levels drop in between meals, insulin will help release that stored sugar from the liver.