What Is Diabetes Mellitus?

Diabetes is a chronic, metabolic disease associated with reduced levels of insulin, a hormone produced by the pancreas, which is essential for the transport of glucose to cells. This lack of insulin secretion and/or increased cellular resistance to insulin results in elevated blood levels of glucose. A person with diabetes cannot properly convert food into the energy needed for daily activities. Diabetes is potentially a very serious condition that can affect the entire body.

Diabetes mellitus, also known as sugar diabetes, is caused by insufficient insulin production or lack of responsiveness to insulin, resulting in hyperglycemia (high blood glucose levels). There are two primary types of diabetes mellitus:

• type I (insulin-dependent, or juvenile-onset), which may be caused by an autoimmune response, and
• type II (non-insulin-dependent or adult-onset).

Type I is the more severe form of the disease. Type II, or adult onset, is the more common form, and accounts for more than 85% of all cases.

Diabetes insipidus is a rare disease, not widely diagnosed, in which the kidneys produce abnormally large volumes of dilute urine. It is most often caused by a deficiency of or lack of responsiveness to the antidiuretic hormone, vasopressin. One form of diabetes insipidus is gestational diabetes, a condition that can develop in women during pregnancy. Symptoms of diabetes include excessive thirst, urination, hunger, or fatigue; unusual weight loss, irritability and blurry vision. 

Diabetes tends to get passed on genetically, but factors other than heredity are responsible as well. Certain medicines, pregnancy, and illnesses that damage the pancreas and affect its ability to produce insulin can also the disease. In October 2004 the Associated Press reported that Polycystic Ovary Syndrome (PCOS) has been linked to the development of diabetes in women. In addition, increasing age, obesity, and lack of physical activity increase the risk of developing the condition.

Complications due to diabetes can include damage to the eyes, kidneys, nervous system and vascular system. It especially affects the tiniest blood vessels in the body, which is why eye care is so important for the diabetic. By the time a mild case of diabetes is diagnosed, some degree of eye damage already may have occurred.

Good blood-sugar management and regular eye checkups, in partnership with your primary care physician or internist, can preserve your vision so that blindness need not be a worry. Diabetes cannot be cured, but it can be controlled. Control requires carefully regulating one's diet, regular exercise, and, if necessary, insulin or other medication. 

Many people are able to work with controlled diabetes, but when diabetes has caused damage to one or more body systems, it may be difficult to work. For information about when you can qualify for disability based on diabetes, see our article on diabetes and disability benefits.