Diagnosing type 2 diabetes

Type 2 diabetesisa manageable condition. Once you’re diagnosed, you can work with your doctor to develop a treatment plan to stay healthy.

Diabetes is grouped into different types. The most commonly diagnosed are gestational diabetes, type 1 diabetes, and type 2 diabetes.

Gestational diabetes

Maybe you have a friend who was told they had diabetes during pregnancy. This type of the condition is called gestational diabetes. It can develop during the second or third trimester of pregnancy. Gestational diabetes usually goes away after the baby is born.

Type 1 diabetes

You may have had a childhood friend with diabetes who had to take insulin every day. That type is called type 1 diabetes. The peak age of onset of type 1 diabetes is the mid-teens. According to the Centers for Disease Control and Prevention (CDC), type 1 makes up 5 percent of all cases of diabetes.

Type 2 diabetes

Type 2 diabetes makes up 90 to 95 percent of all diagnosed cases of diabetes, according to the CDC. This type is also called adult-onset diabetes. Although it can occur at any age, type 2 diabetes is more common in people older than 45.

If you think you might have diabetes, talk to your doctor. Uncontrolled type 2 diabetes can cause severe complications, such as:

According to the CDC, diabetes is the 7th leading cause of death in the United States. Many of the severe side effects of diabetes can be avoided with treatment. That’s why an early diagnosis is so important.

Some people are diagnosed with type 2 diabetes because they have noticeable symptoms. Early symptoms can include:

  • increased or frequent urination
  • increased thirst
  • fatigue
  • cuts or sores that won’t heal
  • blurry vision

Most often, people are diagnosed through routine screening tests. Routine screening for diabetes typically starts at age 45. You may need to be screened sooner if you:

  • are overweight
  • live a sedentary lifestyle
  • have a family history of type 2 diabetes
  • have a history of gestational diabetes or have given birth to a baby weighing over 9 pounds
  • are of African-American, Native American, Latino, Asian, or Pacific Islander descent
  • have a low level of good cholesterol (HDL) or a high triglyceride level

The symptoms of type 2 diabetes often develop gradually. Because you may or may not have symptoms, your doctor will use blood tests to confirm your diagnosis. These tests, listed here, measure the amount of sugar (glucose) in your blood:

  • glycated hemoglobin (A1C) test
  • fasting plasma glucose test
  • random plasma glucose test
  • oral glucose tolerance test

Your doctor will perform one or more of these tests more than once to confirm your diagnosis.

Glycated hemoglobin (A1C) test

The glycated hemoglobin (A1C) test is a long-term measure of blood sugar control. It allows your doctor to figure out what your average blood sugar level has been for the past two to three months.

This test measures the percentage of blood sugar attached to hemoglobin. Hemoglobin is the oxygen-carrying protein in your red blood cells. The higher your A1C is, the higher your recent blood sugar levels have been.

The A1C test isn’t as sensitive as the fasting plasma glucose test or oral glucose tolerance test. This means that it identifies fewer cases of diabetes. Your doctor will send your sample to a certified laboratory for diagnosis. It may take longer to get results than with a test conducted in your doctor’s office.

An advantage of the A1C test is convenience. You don’t have to fast before this test. The blood sample can be collected at any time of day. Also, your test results aren’t affected by stress or illness.

Your doctor will go over your results with you. Here’s what your A1C test results could mean:

  • A1C of 6.5 percent or higher = diabetes
  • A1C between 5.7 and 6.4 percent = prediabetes
  • A1C less than 5.7 percent = normal

This type of testing can also be used to monitor your blood sugar control after you’ve been diagnosed. If you have diabetes, your A1C levels should be checked several times a year.

Fasting plasma glucose test

In some circumstances, the A1C test isn’t valid. For example, it can’t be used for pregnant women or people who have a hemoglobin variant. The fasting blood sugar testing may be used instead. For this test, a sample of your blood will be taken after you’ve fasted overnight.

Unlike the A1C test, the fasting plasma glucose test measures the amount of sugar in your blood at a single point in time. Blood sugar values are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). It’s important to understand that your results can be affected if you’re stressed or sick.

Your doctor will go over your results with you. Here’s what your results could mean:

  • fasting blood sugar of 126 mg/dL or higher = diabetes
  • fasting blood sugar of 100 to 125 mg/dL = prediabetes
  • fasting blood sugar less than 100 mg/dL = normal

Random plasma glucose test

Random blood sugar testing is used in people who have symptoms of diabetes. A random blood sugar test can be done at any time of day. The test looks at blood sugar without considering your last meal.

No matter when you last ate, a random blood sugar test of 200 mg/dL or above suggests that you have diabetes. This is particularly true if you already have symptoms of diabetes.

Your doctor will go over your results with you. Here’s what your test results could mean:

  • random blood sugar of 200 mg/dL or more = diabetes
  • random blood sugar level between 140 and 199 mg/dL = prediabetes
  • random blood sugar less than 140 mg/dL = normal

Oral glucose tolerance test

Like the fasting plasma glucose test, the oral glucose tolerance test also requires you to fast overnight. When you arrive at your appointment, you’ll take a fasting blood sugar test. Then you’ll drink a sugary liquid. After you’re done, your doctor will test your blood sugar levels periodically for several hours.

To prepare for this test, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends that you eat at least 150 grams of carbohydrates per day for the three days leading up to the test. Foods like bread, cereal, pasta, potatoes, fruit (fresh and canned), and clear broth all contain carbohydrates.

Tell your doctor about any stress or illness you’re experiencing. Make sure your doctor knows about all of the medications you’re taking. Stress, illness, and medications can all affect the results of the oral glucose tolerance test.

Your doctor will go over your results with you. For an oral glucose tolerance test, here’s what your results could mean:

  • blood sugar of 200 mg/dL or more after two hours = diabetes
  • blood sugar between 140 and 199 mg/dL after two hours = prediabetes
  • blood sugar less than 140 mg/dL after two hours = normal

Glucose tolerance tests are also used to diagnose gestational diabetes during pregnancy.

You should always feel free to get a second opinion if you have any concerns or doubts about your diagnosis.

If you change doctors, you’ll want to ask for new tests. Different doctors’ offices use different laboratories to process samples. The NIDDK says it can be misleading to compare results from different labs. Remember that your doctor will need to repeat any test to confirm your diagnosis.

Are the test results ever wrong?

Initially, your test results may vary. For instance, a blood sugar test may show that you have diabetes but an A1C test may show that you don’t. The reverse can also be true.

How does this happen? It could mean that you’re in an early stage of diabetes, and your blood sugar levels may not be high enough to show on every test.

The A1C test can be wrong in some people of African, Mediterranean, or Southeast Asian heritage. The test can be too low in people with anemia or heavy bleeding, and too high in people with iron deficiency anemia. Don’t worry — your doctor will repeat the tests before making a diagnosis.

Once you know you have diabetes, you can work with your doctor to create a treatment plan that’s right for you. It’s important to follow through on all your monitoring and medical appointments. Getting your blood tested regularly and tracking your symptoms are essential steps to ensure long-term health.

Talk with your doctor about your blood sugar goal. The National Diabetes Education Program says that the goal for many people is an A1C below 7. Ask your doctor how often you should test your blood sugar.

Create a self-care plan to manage your diabetes. This may include lifestyle changes like eating healthy food, exercising, stopping smoking, and checking your blood sugar.

At every visit, talk to your doctor about how your self-care plan is working.

There’s no existing cure for type 2 diabetes. However, this condition is highly manageable with many effective treatment options.

The first step is diagnosis and understanding your test results. To confirm your diagnosis, you doctor will need to repeat one or more of these tests: A1C, fasting blood glucose, random blood glucose, or oral glucose tolerance.

If you’re diagnosed with diabetes, create a self-care plan, set a blood sugar goal, and check in with your doctor regularly.