Diabetes mellitus is the most common endocrine disorder in the U.S. In 2007, the National Institute of Diabetes and Digestive and Kidney Diseases estimated 23.6 million Americans have diabetes. High blood sugar levels are the hallmark of diabetes. Insulin is a hormone produced by the pancreas, which normally regulates the blood glucose (sugar) level within a narrow range. In diabetes, the blood glucose levels are too high due to abnormal insulin production, impaired insulin actions, or a combination of both. Type 1 diabetes is caused by the loss of insulin-producing cells, leaving a chronic insulin deficit. Type 2 diabetes begins as a disorder of insulin action; the cells of the body do not respond normally to insulin, a condition called insulin resistance. People with type 2 diabetes often have no symptoms. However, a characteristic group of symptoms is often present in people presenting with type 1 diabetes.
Polyuria
Three common symptoms of type 1 diabetes are the 3 P's: polyuria, polydipsia and polyphagia. Polyuria is increased urine production. As the blood glucose level rises, the kidneys are overwhelmed by the sugar overload and glucose spills into the urine--bringing with it a lot of water. The result is loss of large amounts of total body water through increased urine production. This first P, polyuria, causes the second P--polydipsia.
Polydipsia
Polydipsia is the medical term for excessive thirst. Because of the large volume of water being lost through the kidneys due to sugar spillage, the body is at a chronic water deficit. This leads to excessive thirst, which manifests as drinking large quantities of fluids.
Polyphagia
Polyphagia is excessive hunger. Glucose is the primary fuel of the body's cells; without it, the cells are starved for energy. Normally, the circulating blood brings glucose to the cells and insulin facilitate its entry. Without insulin to help glucose get into the cell, it cannot enter. Hence, in type 1 diabetes, there is plenty of blood glucose for the taking, but the cells remain starved because there isn't enough insulin to help the glucose enter. The body responds to the cells' starvation by sending out hunger signals. Indeed, people with type 1 diabetes often eat what seems to be excessive amounts of food. However, the food cannot be utilized normally, which leads to the next symptom--weight loss.
Weight Loss
People with undiagnosed or uncontrolled type 1 diabetes often have unintentional weight loss. They eat sufficient calories and digest their food normally--but the glucose from the food cannot reach its final destination, the body's cells. Without sufficient glucose to fuel the cells, the body breaks down fat and protein to provide backup fuels. The result is often unintentional weight loss, which can be quite rapid and substantial.
Fatigue
Without access to their preferred fuel--glucose--the body's cells struggle to keep up with the energy demands of keeping the body running. Clinically, this manifests as chronic fatigue or lack of energy, which is unrelieved by rest or sleep.
References
- "Harrison's Principles of Internal Medicine, 16th Edition"; Anthony S. Fauci, M.D., Eugene Braunwald, M.D., J. Larry Jameson, M.D., Ph.D., Dennis L. Kasper, M.D., Stephen L. Hauser, M.D., Dan L. Longo, M.D., Editors; 2004
- National Institute of Diabetes and Digestive and Kidney Diseases: National diabetes statistics, 2007
- American Diabetes Association: Symptoms
- Patient UK: Diabetes mellitus
- Merck Manual: Diabetes mellitus
