A chronic condition of the metabolism of proteins, lipids, and carbohydrates is known as diabetes mellitus. A definition of diabetes mellitus is an impaired or insufficient insulin secretory response, which results in impaired utilisation of carbohydrates (glucose) and the subsequent hyperglycemia. The most prevalent endocrine illness, diabetes mellitus (DM), is sometimes known as "sugar" and typically manifests as an absence or shortage of insulin or, less frequently, as an impairment of insulin function.

Classification of Diabetes Mellitus: The World Health Organisation (WHO) issued the first generally accepted classification of diabetes mellitus in the year 1980, and it was updated in the year 1985. insulin-dependent type 2 diabetes. Previously known as juvenile-onset or ketosis-prone diabetes, this type of diabetes mellitus is now classified as autoimmune diabetes. The person may also seek treatment for autoimmune diseases such Addison's disease, Graves' disease. Insulin-dependent diabetes mellitus, often known as type I diabetes, primarily affects children and young adults. Its onset is typically abrupt and can be fatal. Antibodies against glutamic acid decarboxylase, islet cells, or insulin, which recognise the autoimmune mechanisms that result in beta-cell death, are typically present in type 1 diabetes.

Adult-onset diabetes is another name for non-insulin dependent diabetes, often known as type 2 diabetes mellitus. On a backdrop of insulin resistance, the progressive insulin secretor malfunction (American Diabetes Association, 2014). The action of insulin is frequently resistant in those with this kind of diabetes. Both types of long-term problems affect the blood vessels, kidneys, eyes, and nerves, and they are the main reasons for morbidity and mortality from diabetes. Causes include: These patients are more likely to develop macrovascular and microvascular problems due to obesity, sedentary lifestyle, advancing age (affecting middle-aged and older adults), and genetic factor. However, studies like the ones mentioned above cannot distinguish between Type 2 diabetes being caused by insulin resistance, insulin insufficiency, or both.

Pregnancy-Associated Type 2 Diabetes Gestational diabetes mellitus (GDM) is the name for glucose intolerance that develops for the first time or is discovered during pregnancy. Gestational diabetes mellitus (GDM) is a term used to describe both Type 1 diabetes mellitus that develops in pregnant women and undiagnosed, asymptomatic Type 2 diabetes mellitus that is identified during pregnancy. diabetic that is not definitely over diabetic during pregnancy is known as gestational diabetes mellitus (GDM). In the long run, children born to mothers with GDM are at higher risk of obesity and type 2 diabetes in later life, a phenomenon attributed to the effects of intrauterine exposure to hyperglycemia. Gestational diabetes mellitus may develop during pregnancy and may disappear after delivery.