It is estimated that 16 million Americans have diabetes, but as many as half of them do not know it. If left untreated, diabetes can lead to blindness, stroke, kidney failure, heart attack and amputations. However, when detected early and treated correctly, diabetes can be controlled.

So why do so many have this disease and not know it? The symptoms can be subtle and easily overlooked or explained away. Often, diabetes will progress and manifest itself in other life threatening illnesses such as heart disease, neuropathy or kidney failure.

Early diagnosis can save your life. With proper treatment diabetes can be controlled and complications avoided or delayed. Everyone should be aware of this disease and its symptoms, as it is much more common than we ever thought in past years.

The following questions may help determine whether you are at higher risk for diabetes mellitus:

Do you have a family history of diabetes?

Are you overweight?

Are you inactive?

Are you over age 45?

Are you a woman who has delivered a baby weighing more than 9 pounds at birth?

Are you African American, Hispanic, Native American or Asian American?

If you answered "yes" to any of these questions, ask your healthcare provider if you should be checked for diabetes.

There are several warning signs and symptoms of diabetes mellitus. These include:

excessive thirst

frequent urination

unexplained weight loss

blurry vision

fatigue or weakness

tingling or numbness of the hands or feet

frequent skin, gum, bladder or vaginal infections

If you have any of these symptoms, contact your healthcare provider right away. Physicians use two basic tests to diagnose diabetes:

One is the fasting test, when your blood glucose should be below 110mg/dl after an overnight fast (not eating, testing is done before breakfast).

The other is known as an oral glucose tolerance test. The blood glucose should be at a level no higher than 140mg/dl within two hours after drinking a glucose liquid.