Type 2 Diabetes
(Diabetes Type 2 · NIDDM)
In this condition factsheet:
The Facts on Type 2 Diabetes
Diabetes is a condition in which the body cannot properly store and use fuel for energy. The body's main fuel is a form of sugar called glucose, which comes from food (after it's been broken down). Glucose enters the blood and is used by cells for energy. To use glucose, the body needs a hormone called insulin that's made by the pancreas. Insulin is important because it allows glucose to leave the blood and enter the body's cells.
Diabetes develops when the body can't make any or enough insulin, or when it can't properly use the insulin it makes. For some people with diabetes, the body becomes resistant to insulin. In these cases, insulin is still produced, but the body does not respond to the effects of insulin as well. Whether from not enough insulin or the inability to use insulin properly, the result is high levels of glucose in the blood, or hyperglycemia.
There are two main types of diabetes: type 1 diabetes and type 2 diabetes. About 90% of people with diabetes have the type 2 kind. Type 2 diabetes is also called noninsulin-dependent diabetes mellitus (NIDDM) or adult onset diabetes. Although children may have type 2 diabetes, it more commonly starts after age 30 and becomes more common with age. About 15% of people over 70 have type 2 diabetes.
Some people do not have diabetes, but do not handle glucose as well as normal. This is called impaired glucose tolerance (IGT). Up to 40% of people with IGT will eventually develop type 2 diabetes.
Causes of Type 2 Diabetes
In type 2 diabetes, either the pancreas does not make enough insulin or the body does not use it properly. No one knows the exact cause of type 2 diabetes, but it's more likely to occur in people who:
- are over 40 years of age
- are overweight
- have a family history of diabetes
- developed gestational diabetes during a pregnancy
- have given birth to a baby that is more than 4 kg (9 lbs)
- have high blood pressure
- have high cholesterol
- have IGT or impaired fasting glucose
- are of Aboriginal, Hispanic, Asian, South Asian, or South African descent
Symptoms and Complications of Type 2 Diabetes
People with type 2 diabetes may not have symptoms for years or decades, but as the disease progresses, symptoms develop. People with type 2 diabetes may have the following signs and symptoms:
- blurred sight
- decreased sensation or numbness in the hands and feet
- dry, itchy skin
- frequent bladder and vaginal infections
- frequent need to urinate
- increased thirst and hunger
- male impotence (erectile dysfunction)
- slow healing of cuts or sores
- tiredness
Unfortunately, many people with type 2 diabetes go undiagnosed for several years and are not diagnosed until they go to the doctor with complications of diabetes.
High blood sugar levels (hyperglycemia) can lead to a condition called glucose toxicity. This leads to further damage to the pancreas, and the body is less able to produce insulin. Without insulin, glucose levels continue to rise to levels that can cause damage to organs such as the eyes, nerves, and kidneys. These problems are similar to the complications associated with type 1 diabetes.
People with diabetes are at greater risk for problems that involve damage to small blood vessels and nerves due to high levels of glucose in the blood. They are also at a greater risk of developing hardening of large arteries (atherosclerosis), which can result in a heart attack, stroke, or poor blood flow to the legs.
Damage to small blood vessels can affect the eyes, kidneys, and nerves. Damage to eyes, specifically the retina, is called diabetic retinopathy and is the leading cause of blindness. Damage to the kidneys, called diabetic nephropathy, can lead to kidney failure and the need for dialysis. Damage to the nerves that supply the legs and arms and gastrointestinal tract is called neuropathy. Some people with diabetes who develop peripheral neuropathy (damage to the nerves in the legs) and have poor blood flow to the legs may eventually need an amputation.
If blood glucose levels become very high, especially when there are other stresses such as infection, people with type 2 diabetes may become confused, dizzy, and have seizures. This can lead to a condition called non-ketonic hyperglycemia-hyperosmolar coma and requires immediate medical attention.
Fortunately, the complications of diabetes can be prevented, delayed, or slowed by controlling blood glucose levels to as close to the normal range as possible. The normal range is 4.0 mmol/L to 7.0 mmol/L (72 mg/dL to 126 mg/dL).
Last reviewed: July 5, 2010
Did you find what you were looking for on our website? Please let us know.
