24 million Americans have diabetes. The good news is it can be controlled. We've got the sound answers to all your questions.

By Margit Feury Ragland and Sanhita Reddy

A staggering 24 million Americans have diabetes, but 1 out of 4 of those people doesn't even know it. This dangerous disease, in which the body has trouble turning sugar into energy, is the seventh leading cause of death and the number one reason for adult blindness and kidney failure in the U.S. In addition, diabetes can lead to other complications, such as heart disease and stroke. The good news, though, is that this condition can be controlled. We've got the sound answers to all your questions.

I've been so thirsty lately and my friend said I might have diabetes. Could she be right?

Your friend's hunch may be correct; increased thirst is one of the most common symptoms, along with frequent urination, fatigue and blurred vision. Also, if you have an infection that takes a long time to clear up (especially bladder and vaginal infections in women) or dark patches on the folds of your skin, like the back of your neck, alert your doctor—these are all signs that you may be insulin-resistant," says Ann Albright, Ph.D., R.D., director of the Division of Diabetes Translation at the Centers for Disease Control and Prevention and president of healthcare and education at the American Diabetes Association (ADA).

How do I find out if I have diabetes?

The ADA suggests everyone over the age of 45—and anyone overweight—get screened for type 2. The most common test is the fasting blood glucose test. After not eating for eight hours, you get your blood sugar checked. If your glucose level is 126 milligrams per deciliter (mg/dL) or higher, you have diabetes, according to the ADA. Blood glucose between 100 and 125 mg/dL is considered prediabetes, meaning you are at risk for the disease. If your numbers are borderline, you may be given an oral glucose tolerance test: You consume sugar and then have your blood levels checked. Some doctors also use the hemoglobin A1C blood test, which shows how your blood sugar levels fluctuate over several months. Your A1C number should be under 7%.

My mom was diagnosed with diabetes. Does that mean I'll get it too?

A family history of diabetes puts you at increased risk, but so does just being over age 45. The disease is also more common among Alaska natives, Asian-Americans, Pacific Islanders, Hispanics/Latinos, Native Americans and African-Americans. Even if you're in one of these high-risk groups, you can protect yourself by striving for a healthy lifestyle and seeing your doctor regularly for screenings. A recent study found that participants who ate well (a diet rich in fruits and veggies, whole grains, olive oil and nuts) reduced their chances of getting diabetes by nearly 83%. "The key to preventing the development of insulin resistance seems to be a diet rich in fiber," says Miguel Martinez-Gonzalez, M.D., Ph.D., study author and chair of the department of preventive medicine and public health at the University of Navarra in Pamplona, Spain.

I was recently diagnosed with type 2 diabetes but still don't really understand what it is.

First, know that you're not alone—nearly 8% of the population in the U.S. has some form of diabetes. Basically, your body has trouble converting sugar into usable energy. In healthy individuals the hormone insulin does this job. Chances are your body is resistant to or can't produce enough insulin. With type 1, an autoimmune disease often diagnosed in children, the pancreas makes no insulin at all and sufferers are treated with insulin shots. The cause of type 2, formerly known as adult onset, is unknown, but is associated with obesity and inactivity. Unfortunately, today young people are also being diagnosed with type 2 (as many as 50% of children with diabetes have type 2).

If I have diabetes, does that mean I'll be on meds forever?

Not necessarily. Sometimes changing your diet, losing weight and increasing your activity level can control type 2. "Since overeating and a sedentary lifestyle can increase the risk of diabetes, interventions that reduce or improve these factors can almost always improve blood sugar levels," says David M. Nathan, M.D., director of the Diabetes Center at Massachusetts General Hospital in Boston. The beneficial effects can be seen within days or weeks. However, long-term weight loss is difficult for many to maintain, so the majority of patients do require medications, says Dr. Nathan. The first line of defense is typically metformin, which quickly lowers blood glucose with few side effects. It also reduces high LDL (bad) cholesterol and may aid in weight loss. If you can't reach your target glycemic levels with metformin, most doctors suggest trying additional medications. The last resort is often insulin therapy.

I've seen diabetic-friendly foods at the supermarket, but they're pretty pricey. Are they really necessary?

"You don't need to buy foods that are specially designed to be lower in sugar," says Jackie Newgent, R.D., author of The All-Natural Diabetes Cookbook (American Diabetes Association). Many people incorrectly believe that sugar causes or worsens diabetes. It's really the total number of carbs you eat—whether from a slice of chocolate cake or a big plate of pasta—that affects blood glucose levels the most. "If you focus on whole grains and fresh fruits and vegetables, buying and eating healthy food can be inexpensive and tasty," says Newgent.