Many children have had no symptoms before they are diagnosed with type 2 diabetes. Usually, the illness is discovered when a blood or urine test taken for another reason shows diabetes.

A health professional may want to assess your child for type 2 diabetes if he or she has a body mass index (BMI) or weight above the 85th percentile for his or her age and gender or weighs more than 120% of ideal and has any two of these risk factors:⁵

• Family history of type 2 diabetes
• Being a Native American, African-American, Latino, Asian-American, or Pacific Islander
• Signs of not being able to use insulin properly (insulin resistance) or conditions associated with it, such as:
  • The skin problem acanthosis nigricans
  • High blood pressure
  • High cholesterol
  • Higher-than-normal liver enzymes, a sign of inflammation from fat deposited in the liver.
  • Polycystic ovary syndrome, a hormone problem that interferes with ovulation

Some children have very high blood sugar levels at the time of diagnosis. A child with very high blood sugar can become confused, sleepy, or unconscious, and may develop diabetic ketoacidosis (DKA), which is an emergency. DKA is most common in people with type 1 diabetes and in some African-American people who have type 2 diabetes.

If a health professional suspects that your child may have type 2 diabetes, he or she will do a medical history, physical examination, and blood glucose testing. If the results of these tests meet the criteria for diagnosing diabetes established by the American Diabetes Association (ADA), your child has diabetes.

If a child has no diabetes symptoms, two blood tests done on separate days are needed to confirm the diagnosis. Two types of tests used to diagnose diabetes are:

• A blood glucose test. A fasting blood sugar test (done after not eating or drinking for 8 hours) is preferred.
• A glucose tolerance test. The child has a fasting blood sugar test and then drinks a sweet liquid with a certain amount of glucose in it. The child's blood sugar is tested two hours later.

Other possible tests

If it is hard to tell whether your child has type 2 or type 1 diabetes, your doctor may do a C-peptide test or an autoantibodies test. (Autoantibodies are produced when the body's immune system does not work right.) These tests may not be able to distinguish the type of diabetes your child has: getting a definite diagnosis may take months or years. In either case, your child's sugar levels will need to be controlled right away.

Sometimes a health professional will do a quick home blood sugar test or a urine test for sugar to see whether a child may have diabetes. Although these tests are simple and can indicate possible diabetes, additional testing is needed to make sure your child actually has the disease.

Monitoring tests if diagnosed with diabetes