Diabetes is a disorder of metabolism-the way in which your body converts the
food you eat into energy. Most of the food you eat is broken down by
digestive juices into chemicals, including a simple sugar called glucose.
Glucose is your body's main source of energy. After digestion, glucose
passes into your bloodstream, where it is available for cells to take in and
use or store for later use.
In order for your cells to take in glucose, a hormone called insulin must be
present in your blood. Insulin acts as a "key" that unlocks "doors" on cell
surfaces to allow glucose to enter the cells. Insulin is produced by special
cells (called islet cells) in an organ called the pancreas, which is about 6
inches long and lies behind your stomach.
In healthy people, the pancreas automatically produces the right amount of
insulin to enable glucose to enter cells. In people who have diabetes, cells
do not respond to the effects of the insulin that the pancreas produces. If
glucose cannot get inside cells, it builds up in the bloodstream. The
buildup of glucose in the blood-sometimes referred to as high blood sugar or
hyperglycemia (which means "too much glucose in the blood")-is the hallmark
When the glucose level in your blood goes above a certain level, the excess
glucose flows out from the kidneys (two organs that filter wastes from the
bloodstream) into the urine. The glucose takes water with it, which causes
you to urinate frequently and to become extremely thirsty. These two
conditions-frequent urination and unusual thirst-are usually the first
noticeable signs of diabetes. Another symptom you may notice is weight loss,
which results from the loss of calories and water in your urine.
The path toward type 2 diabetes
As you gain weight, the extra weight causes your cells to become resistant to
the effects of insulin. The pancreas responds by producing more and more
insulin, which eventually begins to build up in your blood. High levels of
insulin in the blood-a condition called insulin resistance-may cause problems
such as high blood pressure and harmful changes in the levels of different
fats (cholesterol) in your blood. Insulin resistance, the hallmark of what
doctors sometimes refer to as "syndrome X," is the first step on the path to
type 2 diabetes.
The second step to type 2 diabetes is a condition called impaired glucose
tolerance. Impaired glucose tolerance occurs when your pancreas becomes
exhausted and can no longer produce enough insulin to get glucose out of your
bloodstream into cells. Glucose begins to build up in your blood. If it is
not diagnosed and not treated, this gradual rise in glucose often leads to
type 2 diabetes, high blood pressure, and heart disease-in any order and in
While all these harmful activities are going on inside your body, you...