Normally, an organ called the pancreas produces a hormone called insulin that regulates the level of sugar in our blood.
In diabetes mellitus, the pancreas fails to perform this role adequately. Sufferers may display symptoms such as tiredness, loss of weight, severe thirst, and the passing of large quantities of urine.
Once diagnosed, casualties can lead a relatively normal life with a few modifications. Mild diabetes may be controlled simply by restricting intake of carbohydrates in the diet, or by taking oral medication.
More severe forms, however, will need to be controlled by regular injections of insulin and careful monitoring of energy intake.