Diabetes is a disease in which the body does not make enough or does not properly use insulin, a hormone used to convert sugar (glucose), starches, and other food into energy. While the exact cause of diabetes remains unknown, factors such as
genetics,
obesity, and an inactive
lifestyle can all play a role. Diabetes can increase your risk of heart disease, making it an important risk factor to keep in check.
Types of Diabetes
How Is Diabetes Diagnosed?
Understanding What Your Numbers Mean
The Keys to Treating Diabetes
There are three main types of diabetes: type 1, type 2, and gestational.
In type 1 diabetes, the body’s immune system stops the pancreas from producing the insulin the body needs to process glucose — the sugar that we need for energy. Without glucose, the body literally “starves.” Type 1 diabetes, which is usually diagnosed in children and young adults, is a serious condition, but it can be managed.
In type 2 diabetes, the body does not properly use the insulin it produces. This results in high glucose levels. Eventually, the body cannot produce enough insulin to keep up with its demand. As with type 1, when glucose builds up in the blood instead of going into cells, your body’s cells will starve for energy.
Gestational diabetes is a little like type 2 diabetes. During the later stages of pregnancy, elevated levels of hormones make the body unable to use insulin properly. Women with gestational diabetes also cannot produce enough insulin to meet their increased needs for normal blood glucose regulation. Although this form of diabetes usually goes away after birth, women who have gestational diabetes are more likely to develop type 2 diabetes later in life.
According to the American Diabetes Association (2007), whether you have type 1 or type 2 diabetes, the possible long-term complications can be serious and can include:
- Heart disease
- Eye damage and blindness
- Kidney damage
- Nerve damage
An estimated 21 million Americans have diabetes. And about 57 million Americans have pre-diabetes, a condition in which blood glucose levels are higher than normal but not high enough to be called diabetes. Diabetes is more common in African Americans, Hispanics, Native Americans, and Asian Americans/Pacific Islanders, as well as older people.
Having diabetes makes it very important to get other risk factors, such as high cholesterol, obesity, and high blood pressure, from the red zone (high risk) to the green zone (low risk). According to the National Cholesterol Education Program, people with type 2 diabetes are at the same risk for coronary events as non-diabetics who already have established heart disease. The chart below shows common complications of diabetes and how managing glucose levels can help lower risk.
| Potential Complications |
Estimated Reduction of Risk Complication |
| Impaired kidney function |
30% to 70%
(with better control of blood pressure and blood
glucose levels) |
| Severe vision loss |
50% to 60%
(with proper screening and care) |
| Amputation |
45% to 85%
(with implementation of foot care programs that include regular examinations and patient education) |
| Heart disease and stroke |
20% to 50%
(with improved control of blood pressure and
cholesterol and lipid levels) |
Source: Centers for Disease Control and Prevention
There are a few different tests that doctors use to diagnose diabetes:
- Fasting plasma glucose test — This convenient test measures your blood glucose after you have fasted for at least 8 hours. It is used to detect diabetes or pre-diabetes
- Oral glucose tolerance test — This highly sensitive test, which is used to diagnose diabetes or pre-diabetes, measures your blood glucose after fasting for at least 8 hours and 2 hours after you drink a glucose-containing beverage
- Casual (random) plasma glucose test — With this test, your blood glucose is checked no matter when you ate your last meal. This test, along with other symptoms, is used to diagnose diabetes but not pre-diabetes
Test results that come back positive for diabetes should be confirmed by repeating the fasting plasma glucose test or an oral glucose tolerance test on a different day.
Review the charts below to get a better understanding of the numbers used to measure diabetes. You can use them to find the range for what is considered normal, pre-diabetes, and diabetes for two different types of diabetes tests.
Table 1. Fasting Plasma Glucose Test
| Plasma Glucose Result (mg/dL) |
Diagnosis |
| 99 and below |
Normal |
| 100 to 125 |
Pre-diabetes |
| 126 and above |
Diabetes* |
*Confirmed by repeating the test on a different day.
Table 2. Oral Glucose Tolerance Test
| 2-Hour Plasma Glucose Result (mg/dL) |
Diagnosis |
| 139 and below |
Normal |
| 140 to 200 |
Pre-diabetes |
| Above 200 |
Diabetes** |
**Confirmed by repeating the test on a different day.
If you have been diagnosed with pre-diabetes or diabetes, there are a number of different ways to manage it. Your doctor is your best source for which plan is right for you, so be sure to schedule regular checkups to find out what steps you should take to get your diabetes under control.
Experts say most people with diabetes should try to keep their blood glucose level as close as possible to a normal level. The closer to normal your blood glucose is, the lower the chances of developing serious health problems.
As a general guide, here are a few things you can do every day to help lower your blood glucose:
- Follow a low glycemic diet — A diet low in sugars and starches and high in fiber can help lower glucose levels. For more information about a low-glycemic diet, visit the Diet and Diabetes page
- Be physically active — At least 30 minutes of exercise a day, most, if not all, days of the week, can help. Get tips about how you can develop an exercise plan
- Take your diabetes medicine — There are a number of different treatment options available, but they won’t work if you don’t take them. Learn more about medications and diabetes
- Check your blood glucose regularly — The only way to know if you are keeping your blood glucose in check is by checking your levels every day as directed by your doctor