Diabetes is a disorder of metabolism--the
way our bodies use digested food for growth and energy. Most of the
food we eat is broken down into glucose, the form of sugar in the
blood. Glucose is the main source of fuel for the body.
After digestion, glucose passes into the
bloodstream, where it is used by cells for growth and energy. For
glucose to get into cells, insulin must be present. Insulin is a
hormone produced by the pancreas, a large gland behind the stomach.
When we eat, the pancreas is supposed
to automatically produce the right amount of insulin to move glucose
from blood into our cells. In people with diabetes, however, the
pancreas either produces little or no insulin, or the cells do not
respond appropriately to the insulin that is produced. Glucose builds
up in the blood, overflows into the urine, and passes out of the body.
Thus, the body loses its main source of fuel even though the blood
contains large amounts of glucose.
What Are the Types of
The three main types of diabetes are
Type 1 diabetes is an autoimmune
disease. An autoimmune disease results when the body's system for
fighting infection (the immune system) turns against a part of the
body. In diabetes, the immune system attacks the insulin-producing
beta cells in the pancreas and destroys them. The pancreas then
produces little or no insulin. Someone with type 1 diabetes needs to
take insulin daily to live.
At present, scientists do not know
exactly what causes the body's immune system to attack the beta cells,
but they believe that autoimmune, genetic, and environmental factors,
possibly viruses, are involved. Type 1 diabetes accounts for about 5
to 10 percent of diagnosed diabetes in the United States.
Type 1 diabetes develops most often in
children and young adults, but the disorder can appear at any age.
Symptoms of type 1 diabetes usually develop over a short period,
although beta cell destruction can begin years earlier.
Symptoms include increased thirst and
urination, constant hunger, weight loss, blurred vision, and extreme
fatigue. If not diagnosed and treated with insulin, a person can lapse
into a life-threatening diabetic coma, also known as diabetic
The most common form of diabetes is
type 2 diabetes. About 90 to 95 percent of people with diabetes have
type 2. This form of diabetes usually develops in adults age 40 and
older and is most common in adults over age 55. About 80 percent of
people with type 2 diabetes are overweight. Type 2 diabetes is often
part of a metabolic syndrome that includes obesity, elevated blood
pressure, and high levels of blood lipids. Unfortunately, as more
children and adolescents become overweight, type 2 diabetes is
becoming more common in young people.
When type 2 diabetes is diagnosed, the
pancreas is usually producing enough insulin, but, for unknown
reasons, the body cannot use the insulin effectively, a condition
called insulin resistance. After several years, insulin production
decreases. The result is the same as for type 1 diabetes--glucose
builds up in the blood and the body cannot make efficient use of its
main source of fuel.
The symptoms of type 2 diabetes develop
gradually. They are not as sudden in onset as in type 1 diabetes. Some
people have no symptoms. Symptoms may include fatigue or nausea,
frequent urination, unusual thirst, weight loss, blurred vision,
frequent infections, and slow healing of wounds or sores.
Gestational diabetes develops only
during pregnancy. Like type 2 diabetes, it occurs more often in
African Americans, American Indians, Hispanic Americans, people with a
family history of diabetes. Though it usually disappears after
delivery, the mother is at increased risk of getting type 2 diabetes
later in life.
How Is Diabetes
Before the discovery of insulin in
1921, everyone with type 1 diabetes died within a few years after
diagnosis. Although insulin is not considered a cure, its discovery
was the first major breakthrough in diabetes treatment.
Today, healthy eating, physical
activity, and insulin via injection or an insulin pump are the basic
therapies for type 1 diabetes. The amount of insulin must be balanced
with food intake and daily activities. Blood glucose levels must be
closely monitored through frequent blood glucose checking.
Healthy eating, physical activity, and
blood glucose testing are the basic management tools for type 2
diabetes. In addition, many people with type 2 diabetes require oral
medication and insulin to control their blood glucose levels.
People with diabetes must take
responsibility for their day-to-day care. Much of the daily care
involves keeping blood glucose levels from going too low or too high.
When blood glucose levels drop too low from certain diabetes
medicines--a condition known as hypoglycemia--a person can become
nervous, shaky, and confused. Judgment can be impaired. If blood
glucose falls too low, a person can faint.
A person can also become ill if blood
glucose levels rise too high, a condition known as hyperglycemia.
People with diabetes should see a
doctor who helps them learn to manage their diabetes and monitors
their diabetes control. An endocrinologist is one type of doctor who
may specialize in diabetes care. In addition, people with diabetes
often see ophthalmologists for eye examinations, podiatrists for
routine foot care, and dietitians and diabetes educators to help teach
the skills of day-to-day diabetes management.
The goal of diabetes management is to
keep blood glucose levels as close to the normal range as safely
possible. A major study showed that keeping blood glucose levels as
close to normal as safely possible reduces the risk of developing
major complications of type 1 diabetes.
Click here for a
suggested diet for those with diabetes.