Diabetes mellitus is a chronic/metabolic disease that results when the pancreas does not produce enough insulin (i.e. a defect in its secretion) or when the body cannot effectively use the insulin it produces (i.e. a defect in its action) or both, thus leading to hyperglycemia―a condition, wherein an increased concentration of glucose in the blood is observed. This further damages many of the body's systems, in particular the blood vessels and nerves.
Diabetes mellitus is categorized into several types on the basis of etiology. The two most common are:
Other forms of diabetes include congenital diabetes (due to genetic defects of insulin secretion), cystic fibrosis-related diabetes, gestational diabetes (hyperglycemia that is first recognized during pregnancy) and steroid diabetes (induced by high doses of glucocorticoids).
Diabetes can lead to other serious conditions as uncontrolled glucose levels affect many parts of the body. Diabetics are vulnerable to various short- and long‑term complications, such as high blood pressure, elevated levels of blood LDL cholesterol, blindness and other eye problems, nerve disease, non-alcoholic fatty liver disease, periodontal (gum) disease, hearing loss, erectile dysfunction, depression, complications of pregnancy, heart disease, stroke, kidney failure, and premature death.
Diabetes can be managed by lifestyle and diet modifications, and medications to lower the blood glucose levels. Effective patient education on self-care practices stressing the importance of healthful eating and regular exercise is the key in managing the disease, and can help people with diabetes stay healthy.