New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Diabetes

Diabetes mellitus, often simply diabetes, is a syndrome characterized by disordered metabolism and inappropriately high blood sugar (hyperglycemia) resulting from either low levels of the hormone insulin or from abnormal resistance to insulin's effects coupled with inadequate levels of insulin secretion to compensate. The characteristic symptoms are excessive urine production (polyuria), excessive thirst and increased fluid intake (polydipsia), and blurred vision; these symptoms may be absent if the blood sugar is mildly elevated.

Prolonged high blood glucose causes glucose absorption, which leads to changes in the shape of the lenses of the eyes, resulting in vision changes. Blurred vision is a common complaint leading to a diabetes diagnosis; type 1 should always be suspected in cases of rapid vision change whereas type 2 is generally more gradual, but should still be suspected.

The World Health Organization recognizes three main forms of diabetes mellitus: type 1, type 2, and gestational diabetes (occurring during pregnancy), which have similar signs, symptoms, and consequences, but different causes and population distributions. Ultimately, all forms are due to the beta cells of the pancreas being unable to produce sufficient insulin to prevent hyperglycemia. Type 1 diabetes is usually due to autoimmune destruction of the pancreatic beta cells, which produce insulin. Type 2 diabetes is characterized by insulin resistance in target tissues, but some impairment of beta cell function is necessary for its development. Gestational diabetes is similar to type 2 diabetes, in that it involves insulin resistance; the hormones of pregnancy can cause insulin resistance in women genetically predisposed to developing this condition.

Related Stories
 


Health & Medicine News

July 29, 2025

A global study of over 88,000 adults reveals that poor sleep habits—like going to bed inconsistently or having disrupted circadian rhythms—are tied to dramatically higher risks for dozens of diseases, including liver cirrhosis and gangrene. ...
Scientists at Columbia Engineering have developed an injectable hydrogel made from yogurt-derived extracellular vesicles (EVs) that could revolutionize regenerative medicine. These EVs serve both as healing agents and as structural components, ...
Fast walking, even just 15 minutes a day, can dramatically reduce the risk of death, especially from heart disease, according to a large study involving nearly 80,000 low-income and predominantly Black Americans in the South. The findings not only ...
A mysterious gut hormone may be behind many cases of chronic diarrhea, especially in people with undiagnosed bile acid malabsorption, a condition often mistaken for irritable bowel syndrome. Researchers from the University of Cambridge identified ...
Walking just a bit faster could be the key to aging well. Researchers found that older adults who upped their walking pace by just 14 steps per minute significantly improved their physical abilities—even those who were already frail. A new, ...
Eggs are finally being vindicated after decades of cholesterol-related blame. New research from the University of South Australia reveals that eggs, despite their cholesterol content, aren't the dietary villains they've long been made out to be. ...
Over-the-counter (OTC) products like St John’s Wort and omega-3s have long been touted for helping with depression, but new research reveals that 64 different OTC products have been tested in ...
Many people with dementia endure long delays often over 3 years before receiving a diagnosis, with even longer waits for younger patients. A global review of over 30,000 cases reveals that age, dementia type, and systemic healthcare issues like ...
A team of scientists has developed a remarkable new approach to modeling how cells behave over time—using a digital "forecast" much like predicting the weather. By combining patient genomics with a groundbreaking plain-language “hypothesis ...
Between 2020 and 2024, COVID-19 vaccines saved 2.5 million lives globally, preventing one death for every 5,400 doses. A groundbreaking worldwide study led by researchers from Università Cattolica and Stanford University reveals that most lives ...
Scientists at UCSF have uncovered how certain immune cells in the brain, called microglia, can effectively digest toxic amyloid beta plaques that cause Alzheimer’s. They identified a key receptor, ...
Scientists at the University of Toronto have developed a new non-stick material that rivals the performance of traditional PFAS-based coatings while using only minimal amounts of these controversial ...

Latest Headlines

updated 12:56 pm ET