Home Blog Pathophysiology and symptoms of diabetes mellitus

Brief discussion on pathophysiology and symptoms of diabetes mellitus

Deficiency of insulin plays a major role in all forms of diabetes mellitus. In diabetes, insulin is one of the primary hormone that controls the uptake of glucose from the blood into cells. Except for smooth muscle, where insulin functions through the insulin-like growth factor (IGF-1) in most body cells, including the liver, adipose tissue, and muscle (1). The breakdown of glycogen i.e., glycogenolysis, the liver’s storage form of glucose, intestinal absorption of meals, and gluconeogenesis, the body’s process for producing glucose from non-carbohydrate substrates, are the three main sources of glucose for the body. As insulin plays an important role in maintaining blood glucose levels in the body. Insulin which is released into the blood by beta cells of the pancreas, present in the islets of Langerhans inhibit the breakdown of glycogen or prevent the process of gluconeogenesis, it can be stimulated by the transport of glucose into fat and muscle cells, and it can stimulate the storage of glucose in the form of glycogen (2). Insulin is released in reaction to increased blood glucose levels, usually after eating. About two-thirds of the body’s cells utilise it to take glucose from the blood and use it as fuel or energy, transform it into other molecules they require, or store it. Lower glucose levels cause the beta cells to release less insulin and cause the breakdown of glycogen into glucose.

The other hormone glucagon released from alpha cells of pancreas, which functions differently from insulin and is primarily responsible for controlling this process (3). The body’s cells that need glucose cannot adequately absorb it, and it cannot be properly stored in the liver and muscles if there is not enough insulin available, cells do not respond well to insulin’s effects (insulin resistance), or the insulin itself is flawed. Overall, this leads to high blood glucose levels that don’t go down, inadequate protein synthesis, and other metabolic abnormalities such metabolic acidosis in cases of severe insulin shortage (4). When the blood glucose level is high for an extended period of time, the kidneys approach a reabsorption threshold and the body excretes glucose in the urine known as glycosuria. As a result, there is a rise in the osmotic pressure of the urine, increased polyuria, and greater fluid loss because the kidneys are unable to reabsorb water. Dehydration and increased thirst are brought on by the body’s osmotic replacement of lost blood volume with water from the body’s cells and other compartments. Additionally, low intracellular glucose increases hunger, which causes overeating (polyphagia)(5).

Unintentional weight loss, polyuria i.e., increased urine, polydipsia i.e., increasing thirst, and polyphagia that is increasing of appetite are the typical signs of untreated diabetes. In type 1 diabetes, symptoms may appear suddenly within weeks or months, whereas they do so much more gradually in type 2 diabetes and may even not appear at all. Although they are not specific to the disease, a number of additional signs and symptoms can indicate the beginning of diabetes. They also include itching skin, impaired vision, headaches, and weariness in addition to the previously mentioned symptoms. Long-term high blood sugar levels can result in glucose absorption in the eye’s lens, which alters the curvature of the lens and alters vision. Diabetic retinopathy can potentially result in long-term vision loss (6).


1.      Winifred U, Alexander M. Biochemical Studies of the Ameliorating Effects of Bitter Leaf and Scent Leaf Extracts on Diabetes Mellitus in Humans. IJCCP. 2018;4(1):29-46.


3.      Barrett KE. Ganong’s review of medical physiology. 2019.

4.      Murray RK, Granner DK, Rodwell VW. Harper’s illustrated biochemistry2010.

5.      Mogotlane S, Shauke M, Matlakala M, Mokoena J, Young A. Juta’s Complete Textbook of Medical Surgical Nursing.(1stedn). Juta, Cape Town. 2013.

6.      Rockefeller J. Diabetes: symptoms, causes, treatment and prevention: JD Rockefeller; 2015.

Submitted by-

Jayshri Swarnkar

Assistant Professor

Faculty of Pharmacy

Kalinga University

Kalinga Plus is an initiative by Kalinga University, Raipur. The main objective of this to disseminate knowledge and guide students & working professionals.
This platform will guide pre – post university level students.
Pre University Level – IX –XII grade students when they decide streams and choose their career
Post University level – when A student joins corporate & needs to handle the workplace challenges effectively.
We are hopeful that you will find lot of knowledgeable & interesting information here.
Happy surfing!!

  • Free Counseling!