“Glucose — a sugar — is a source of energy for the cells that make up muscles and other tissues.

• Glucose comes from two major sources: food and the liver.
• Sugar is absorbed into the bloodstream, where it enters cells with the help of insulin.
• The liver stores and makes glucose.
• When glucose levels are low, such as when you haven’t eaten in a while, the liver breaks down stored glycogen into glucose. This keeps your glucose level within a typical range.

Insulin is a hormone that comes from a gland behind and below the stomach (pancreas).

• The pancreas releases insulin into the bloodstream.
• The insulin circulatesl allowing the sugar enter the cells.  Without insulin or enough of insulin in our bodies the glucose level becomes severely low=Diabetes and hyperglycemia because the glucose stays outside the cells and in the bloodstream.
• Insulin lowers the amount of sugar in the bloodstream by allowing the insulin to pass through the membrane of our cells for energy = cellular starvation.
• As the blood sugar level drops, so does the secretion of insulin from the pancreas.
• The exact cause of Diabetes in most cases is unknown etiology.”

MAYO CLINIC (Diabetes – Symptoms and causes – Mayo Clinic)