Diabetes Basics

Return to main article:

Diabetes has two main variants: type 1 and type 2. Both result from a defect in the body’s insulin-producing mechanism, but the way they develop is quite different.

Insulin, the hormone that signals the body to take up circulating glucose from the blood, is produced by beta cells in the pancreas. That organ, lodged beneath the stomach, is roughly the size and shape of a banana; in a healthy person, the all-important beta cells, taken together, have the volume of the first joint of a pinkie finger.

Type 1 diabetes is an autoimmune disease: a person’s own immune system attacks the beta cells, for reasons that are not well understood. Type 2 diabetes, the form associated with obesity, delivers a double whammy: cells in muscles, fat, and the liver become resistant to insulin’s effects, and the beta cells compensate by pumping it out in ever higher amounts. Although medications and lifestyle changes—such as weight loss and exercise—to increase insulin sensitivity are a first line of defense, many patients ultimately need injected insulin to balance their blood glucose after their beta cells fail altogether.

This article deals mainly with type 2 diabetes, the form that is linked to the obesity epidemic and modern lifestyle factors. (This is the variant that has commonly been called adult-onset diabetes, but it is increasingly affecting children, too.) To read about recent advances in the treatment of type 1 diabetes, often called juvenile diabetes, see “Stem-Cell Progress,” page 63.

You might also like

Historic Humor

University Archives to preserve Harvard Lampoon materials

Academia’s Absence from Homelessness

“The lack of dedicated research funding in this area is a major, major problem.”

The Enterprise Research Campus, Part Two

Tishman Speyer signals readiness to pursue approval for second phase of commercial development.  

Most popular

Claudine Gay in First Post-Presidency Appearance

At Morning Prayers, speaks of resilience and the unknown

Poise, in Spite of Everything

Nina Skov Jensen ’25, portraitist for collectors and the princess of Denmark. 

The Gravity of Groups

Mina Cikara explores how political tribalism feeds the American bipartisan divide.

More to explore

Exploring Political Tribalism and American Politics

Mina Cikara explores how political tribalism feeds the American bipartisan divide.

Private Equity in Medicine and the Quality of Care

Hundreds of U.S. hospitals are owned by private equity firms—does monetizing medicine affect the quality of care?

Construction on Commercial Enterprise Research Campus in Allston

Construction on Harvard’s commercial enterprise research campus and new theater in Allston