Diabetes Mellitus, commonly referred to as "diabetes," means "sweet urine." Diabetes mellitus means "to flow, honey" in Greek. Diabetes is a disease that affects the body's ability to produce or respond to insulin, a hormone that allows blood glucose (blood sugar) to enter the cells of the body and be used for energy. It results from defects in insulin secretion, insulin action, or both. In diabetes too much glucose stays in the blood. Elevated levels of blood glucose (hyperglycemia) lead to spillage of glucose into the urine.

Our bodies are made up of groups of cells, each cell so tiny it is invisible to the naked eye. These cells reproduce themselves by dividing in a regular way so growth and repair of body tissues can take place. Cancer develops when cells start to divide at the wrong time and in the wrong place, then continue to divide and invade nearby tissues and organs. It is this uncontrolled growth of cells that causes a swelling or tumour.

The mesotheleumhelps protect the organs by producing a special lubricating fluid that allows organs to move around. For example, this fluid makes it easier for the lungs to move inside the chest during breathing. The mesothelium of the chest is called the pleura and the mesothelium of the abdomen is known as the peritoneum. The mesothelium of the pericardial cavity (the "sac-like" space around the heart) is called the pericardium