Diabetes is a serious disease that often comes with a stigma about poor eating habits and obesity. Even though it affects more than 9 percent of the population— almost 1 in 10 Americans— the lack of common knowledge surrounding the disease can make life difficult for its sufferers.

Worse, nearly a third of people with diabetes don’t know they have it, according to the Centers for Disease Control and Prevention (CDC). That means there are about 8 million Americans who are diabetic and don’t know it and, as such, are making uninformed health choices. Even if you’re not diabetic, it probably affects someone you know.

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Here’s a chance to brush up on the facts by dispelling myths about diabetes.

MYTH: The Main Cause of Diabetes Is Obesity or Too Much Sugar

Diabetes is commonly associated with obesity and sugar consumption. Perhaps because of these associations, it’s easy to boil the disease down to those two main culprits. However, diabetes isn’t so simple.

There are many types of diabetes, but the most commonly known are type I and type II diabetes, and gestational diabetes. Types I and II are caused by genetic factors among other triggers, while gestational diabetes is caused by hormone fluctuations during pregnancy. Some types of diabetes are caused by medications or surgery and may be temporary or permanent.

High sugar consumption and obesity are most frequently associated with type II diabetes and are indeed risk factors for the disease. However, most obese people do not have diabetes, and many people with type II diabetes are only moderately overweight or are of a normal weight.

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MYTH: Diabetics Are More Likely to Get the Flu

Experts recommend people with diabetes get a flu shot every year, so some people think they’re at an increased flu risk. On the contrary, people with diabetes are no more likely to get viral infections like influenza or the common cold than people without the disease.

Doctors suggest that people with diabetes get a flu shot every year because the flu virus can complicate diabetes and make it more difficult to control. The same goes for most viral illnesses, but studies have shown that diabetics who get the flu are more likely to develop serious complications later.

MYTH: Diabetics Must Follow a Strict Diet

When some diabetics are first diagnosed, they may fear that sweets and carbs are out of their lives for good. However, the recommended diet for controlling diabetes is not very different from a standard healthy diet we should all follow to maintain good health. Sweets and carbs may need to be limited to control diabetes, but even desserts can be incorporated into a healthy diabetic diet, according to the American Diabetes Association.

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MYTH: Only Those Who Didn’t Control Their Disease Properly Have to Take Insulin

Insulin pumps, and the need to use insulin in general, are part of more serious stages of diabetes. Because some people can successfully control their diabetes with diet and exercise, it can be easy to assume those who use insulin just didn’t care for themselves well early on.

But type II diabetes often progresses naturally— even when the affected person possesses healthy habits. In people with type I diabetes, the pancreas produces little or no insulin on its own, so the person with the condition must take it via pump or injection from a young age.

MYTH: Gestational Diabetes Goes Away on Its Own, so It’s No Big Deal

During pregnancy, a woman’s hormones can go a little haywire, including the hormones that affect digestion. In gestational diabetes, these hormonal fluctuations make the body less able to use insulin properly. It’s true that most gestational diabetes goes away after giving birth.

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However, gestational diabetes is a risk factor for type II diabetes later in life for mother and child, so precautionary steps should be taken to prevent it. This includes healthy eating, regular exercise and avoiding obesity.