context: There are three major types of the disease: type 1, type 2, and gestational diabetes. With all three, your body can't make or use insulin. One of every four people with diabetes doesn't know they have it. That amounts to about 7 million Americans. Might you be one of them? Read on to see if your risk of having diabetes is high. This type usually starts in childhood. Your pancreas stops making insulin. You have type 1 diabetes for life. The main things that lead to it are: Family history. If you have relatives with diabetes, chances are higher that you'll get it, too. Anyone who has a mother, father, sister, or brother with type 1 diabetes should get checked. A simple blood test can diagnose it. Diseases of the pancreas. They can slow its ability to make insulin. Infection or illness. Some infections and illnesses, mostly rare ones, can damage your pancreas. If you have this kind, your body can't use the insulin it makes. This is called insulin resistance. Type 2 usually affects adults, but it can begin at any time in your life. The main things that lead to it are: Obesity or being overweight. Research shows this is a top reason for type 2 diabetes. Because of the rise in obesity among U. S. children, this type is affecting more teenagers. Impaired glucose tolerance. Prediabetes is a milder form of this condition. It can be diagnosed with a simple blood test. If you have it, there's a strong chance you'll get type 2 diabetes. Insulin resistance. Type 2 diabetes often starts with cells that are resistant to insulin. That means your pancreas has to work extra hard to make enough insulin to meet your body's needs. Ethnic background. Diabetes happens more often in Hispanic/ Latino Americans, African- Americans, Native Americans, Asian- Americans, Pacific Islanders, and Alaska natives. Gestational diabetes. If you had diabetes while you were pregnant, you had gestational diabetes. This raises your chances of getting type 2 diabetes later in life. Sedentary lifestyle. You exercise less than three times a week. Family history. You have a parent or sibling who has diabetes. Polycystic ovary syndrome. Women with polycystic ovary syndrome ( PCOS) have a higher risk. Age. If you're over 45 and overweight or if you have symptoms of diabetes, talk to your doctor about a simple screening test. Diabetes when you're expecting affects about 4% of all U. S. pregnancies. It's caused by hormones the placenta makes or by too little insulin. High blood sugar from the mother causes high blood sugar in the baby. That can lead to growth and development problems if left untreated. Things that can lead to gestational diabetes include: Obesity or being overweight. Extra pounds can lead to gestational diabetes. Glucose intolerance. Having glucose intolerance or gestational diabetes in the past makes you more likely to get it again. Family history. If a parent or sibling has had gestational diabetes, you're more likely to get it. Age. The older you are when you get pregnant, the higher your chances are. Ethnic background. Nonwhite women have a greater chance of developing it. Whatever your risk are, there's a lot you can do to delay or prevent diabetes. Manage your blood pressure. Keep your weight within or near a healthy range. Get 30 minutes of exercise on most days. Eat a balanced diet.