Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic disorders that are characterized by high blood sugar levels over a long period of time. Symptoms often include frequent urination, increased thirst, and appetite. If left untreated, diabetes can create a host of problems. Major long-term complications include heart disease, stroke, chronic kidney disease, foot ulcers, nerve damage, eye damage and intellectual disability. Diabetes is either because the pancreas does not produce enough insulin, or the body's cells do not respond well to insulin that is produced. There are three main types of diabetes mellitus. The classic symptoms of diabetes can be treated for unintended weight loss, polyuria (increased urination), polydipsia (increased thirst), and polyphagia (increased hunger). Symptoms can develop rapidly (weeks or months) in type 1 diabetes, while they tend to grow slowly and may be subtle or absent in type 2 diabetes. A few other signs and symptoms may mark the onset of diabetes even though they are not specific to the disease.