Diabetes is a chronic health condition characterized by elevated levels of blood glucose, often referred to as blood sugar. This occurs when the body either does not produce enough insulin or cannot effectively use the insulin it produces.
How the Body Manages Blood Sugar
The body converts food into energy through a process that regulates blood sugar levels. When carbohydrates from food are consumed, they are broken down into glucose, a simple sugar that serves as the body’s primary energy source. This glucose then enters the bloodstream, causing blood sugar levels to rise.
In response to this increase, the pancreas, an organ located behind the stomach, releases a hormone called insulin. Insulin acts like a key, allowing glucose to move from the bloodstream into cells throughout the body, such as muscle, fat, and liver cells, where it is used for immediate energy or stored for later use. This action of insulin ensures that blood glucose levels remain within a healthy range, a state known as glucose homeostasis.
Type 1 Diabetes: An Autoimmune Development
Type 1 diabetes develops when the body’s immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. This is an autoimmune disease, where the immune system targets its own healthy cells.
The destruction of beta cells means the pancreas produces little to no insulin. Without sufficient insulin, glucose cannot enter the body’s cells, leading to a buildup of sugar in the bloodstream. This autoimmune process can occur over months or years before symptoms become apparent.
While often diagnosed in childhood or adolescence, type 1 diabetes can manifest at any age. Genetic predisposition plays a role, and environmental triggers, such as viruses, are thought to initiate the autoimmune attack. There is no known way to prevent type 1 diabetes.
Type 2 Diabetes: The Progression of Insulin Resistance
Type 2 diabetes, the most common form, typically develops due to insulin resistance. In this scenario, the body’s cells become less responsive to insulin, meaning glucose struggles to enter them even when insulin is present.
This reduced sensitivity forces the pancreas to work harder, initially producing more insulin to overcome the resistance and maintain normal blood sugar levels. Over time, this overcompensation can exhaust the beta cells in the pancreas, leading to pancreatic fatigue or even failure.
The pancreas eventually becomes unable to produce enough insulin to manage blood sugar effectively, resulting in elevated glucose levels. Excess body fat, particularly around the abdomen, and a lack of physical activity are contributors, as they can worsen cellular unresponsiveness to insulin. Genetic predispositions, unhealthy dietary patterns, and age also increase the likelihood of developing this condition.
Gestational and Other Pathways to Diabetes
Gestational diabetes develops exclusively during pregnancy when hormonal changes interfere with the body’s ability to use insulin effectively. Hormones produced by the placenta can create insulin resistance, causing glucose to accumulate in the bloodstream.
While it typically resolves after childbirth, gestational diabetes increases the mother’s risk of developing type 2 diabetes later in life.
Beyond these common types, diabetes can also arise from other less frequent causes. Certain medications, such as steroids, can induce temporary or permanent diabetes by affecting insulin sensitivity or production. Specific genetic mutations can lead to monogenic forms of diabetes, where a single gene defect impairs insulin function. Additionally, diseases that damage the pancreas, like chronic pancreatitis or cystic fibrosis, can destroy insulin-producing cells and result in diabetes.