Description

Diabetes mellitus (DM), commonly referred toasdiabetes, is a group of metabolic diseases in which there arehighblood sugar levels over a prolonged period. Symptoms of highbloodsugar include frequent urination, increased thirst, andincreasedhunger. If left untreated, diabetes can cause manycomplications.Acute complications include diabetic ketoacidosisand nonketotichyperosmolar coma. Serious long-term complicationsincludecardiovascular disease, stroke, kidney failure, foot ulcersanddamage to the eyes.

Diabetes is due to either the pancreas not producingenoughinsulin or the cells of the body not responding properly totheinsulin produced. There are three main types ofdiabetesmellitus:

Type 1 DM results from the body's failure to produceenoughinsulin. This form was previously referred to as"insulin-dependentdiabetes mellitus" (IDDM) or "juvenile diabetes".The cause isunknown.
Type 2 DM begins with insulin resistance, a condition in whichcellsfail to respond to insulin properly. As the diseaseprogresses alack of insulin may also develop. This form waspreviously referredto as "non insulin-dependent diabetes mellitus"(NIDDM) or"adult-onset diabetes".

Prevention and treatment involves a healthy diet,physicalexercise, not using tobacco and being a normal body weight.Bloodpressure control and proper foot care are also important forpeoplewith the disease. Type 1 diabetes must be managed withinsulininjections. Type 2 diabetes may be treated with medicationswith orwithout insulin. Insulin and some oral medications can causelowblood sugar. Weight loss surgery in those with obesity isaneffective measure in those with type 2 DM. Gestationaldiabetesusually resolves after the birth of the baby.

The classic symptoms of untreated diabetes are weightloss,polyuria (frequent urination), polydipsia (increased thirst),andpolyphagia (increased hunger). Symptoms may develop rapidly(weeksor months) in type 1 diabetes, while they usually developmuch moreslowly and may be subtle or absent in type 2 diabetes.

Several other signs and symptoms can mark the onset ofdiabetes,although they are not specific to the disease. In additionto theknown ones above, they include blurry vision, headache,fatigue,slow healing of cuts, and itchy skin. Prolonged high bloodglucosecan cause glucose absorption in the lens of the eye, whichleads tochanges in its shape, resulting in vision changes. A numberof skinrashes that can occur in diabetes are collectively knownasdiabetic dermadromes.

People (usually with type 1 diabetes) may alsoexperienceepisodes of diabetic ketoacidosis, a type of metabolicproblemscharacterized by nausea, vomiting and abdominal pain, thesmell ofacetone on the breath, deep breathing known as Kussmaulbreathing,and in severe cases a decreased level ofconsciousness.

A rare but equally severe possibility is hyperosmolarnonketoticstate, which is more common in type 2 diabetes and ismainly theresult of dehydration.

Type 1 diabetes mellitus is characterized by loss oftheinsulin-producing beta cells of the islets of Langerhans inthepancreas, leading to insulin deficiency. This type can befurtherclassified as immune-mediated or idiopathic. The majority oftype 1diabetes is of the immune-mediated nature, in whichaT-cell-mediated autoimmune attack leads to the loss of betacellsand thus insulin. It causes approximately 10% of diabetesmellituscases in North America and Europe. Most affected peopleareotherwise healthy and of a healthy weight when onsetoccurs.Sensitivity and responsiveness to insulin are usuallynormal,especially in the early stages. Type 1 diabetes can affectchildrenor adults, but was traditionally termed "juvenile diabetes"becausea majority of these diabetes cases were in children.