Diabetes is a metabolic disease that can lead to serious health complications if left untreated. Several factors, such as body weight, family history and race and ethnicity may increase your risk of diabetes. Diabetes can be effectively managed by exercising and eating a healthy diet.
What is diabetes?
Diabetes (medically known as diabetes mellitus) is a common, chronic disorder marked by elevated levels of blood glucose, or sugar. It occurs when your cells don’t respond appropriately to insulin (a hormone secreted by the pancreas), and when your pancreas can’t produce more insulin in response.
Diabetes usually can’t be cured. Left untreated—or poorly managed—it can lead to serious long-term complications, including kidney failure, amputation, and blindness. Moreover, having diabetes increases your risk for cardiovascular disease, including heart attack and stroke.
Your body and sugar
To understand diabetes, it’s helpful to understand the basics of how your body metabolizes (breaks down) sugar. Most of the cells in your body need sugar as a source of energy. When you eat carbohydrates, such as a bowl of pasta or some vegetables, your digestive system breaks the carbohydrates down into simple sugars such as glucose, which travel into and through your bloodstream to nourish and energize cells.
A key player in the breakdown of sugar is the pancreas, a fish-shaped gland behind your stomach and liver. The pancreas fills two roles.
It produces enzymes that flow into the small intestine to help break down the nutrients in your food—proteins, carbohydrates, and fats—to provide sources of energy and building material for the body’s cells.
It makes hormones that regulate the disposal of nutrients, including sugars.
Cells in the pancreas, called beta cells, release insulin in response to the rise in blood sugar levels after you’ve eaten a meal. By directing sugar into liver and muscle cells, insulin promotes nutrient storage and prevents blood sugar levels from rising excessively.
Insulin also increases the uptake of amino acids (the building blocks of proteins) and fatty acids (the building blocks of fats) into protein and fat stores, respectively. Insulin thus serves as one of the principal gatekeepers of metabolism, promoting energy storage and cell growth.
The liver converts glucose that is not needed immediately for energy into a storage molecule called glycogen. When blood glucose levels drop too low, insulin secretion falls and your pancreas releases the hormone glucagon, which prompts your liver to reconvert stored glycogen into glucose and release it into the bloodstream.
Usually insulin and glucagon levels fluctuate in a coordinated fashion to keep your blood glucose levels within a rather narrow range. This is important because certain organs, such as the brain and kidneys, depend on a consistent, steady supply of glucose. A normally functioning pancreas ensures a stable supply of nutrients for your body.
In healthy people, insulin prevents a large rise in blood sugar after eating. The normal blood sugar level before breakfast usually hovers between 70 and 110 milligrams per deciliter (mg/dL). Normal levels of sugar in the blood rarely exceed 180 mg/dL, even after a meal.