Understanding a Type 2 Diabetes Diagnosis

Written by Brett Huffman | Published on August 28, 2014
Medically Reviewed by Peggy Pletcher, MS, RD, LD, CDE on August 28, 2014

Diagnosing Type 2 Diabetes

Being diagnosed with Type 2 diabetes can come as a real shock. It can be scary to hear that you have a lifelong health problem. However, a diagnosis can actually help you improve your health. Type 2 diabetes is a manageable condition. Once you’re diagnosed, you can learn what to do to stay healthy. It just requires some changes and a commitment to living a healthier lifestyle.

If you think you might have diabetes, talk to your doctor. Uncontrolled Type 2 diabetes can cause severe complications like:

  • blindness
  • heart disease
  • kidney disease
  • lower limb amputation

According to the Centers for Disease Control and Prevention (CDC), diabetes is the seventh leading cause of death in the United States. People with diabetes are twice as likely to die as people of the same age who don’t have diabetes.

Many of the severe side effects of diabetes can be avoided with treatment. That’s why it’s so important to be diagnosed as soon as possible.

Screening for Type 2 Diabetes

Some people are diagnosed with Type 2 diabetes because they have symptoms. Early diabetes symptoms 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. In general, routine screening for diabetes 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 over 9 pounds
  • are of certain ethnicity (African American, Native American, Latino, Asian, and Pacific Islander)
  • have a low good cholesterol level (HDL) or a high triglyceride level

How Doctors Diagnose Type 2 Diabetes

A number of tests can be used to detect Type 2 diabetes.

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 few 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 hemoglobin A1C is, the higher your recent blood sugar levels have been. 

An A1C level of 6.5 percent or higher on two different tests indicates that you have diabetes. A result between 5.7 and 6.4 percent indicates prediabetes. Normal levels are below 5.7 percent.

Hemoglobin A1C testing can also be used to monitor your blood sugar control after you’ve been diagnosed. Your A1C levels should be checked several times a year.

Fasting Glucose Test

Your doctor may also opt for a fasting blood sugar test. In this case, a sample of your blood will be taken after you have fasted overnight.

A normal fasting blood sugar level is less than 100 mg/dL (5.6 mmol/L). A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) indicates prediabetes. If your test shows a level of 126 mg/dL (7 mmol/L) or higher on two different tests, you have Type 2 diabetes.

Random (Non-Fasting) Blood Glucose Test

There are certain circumstances in which a hemoglobin A1C test is not valid. For example, it can’t be used by pregnant women, or by people who have a hemoglobin variant. For these people, random blood sugar testing may be used instead.

A random blood sugar test can be done at any time. It looks at blood sugar without considering your last meal.

Blood sugar values are expressed in milligrams per decileter (mg/dL) or millimoles per liter (mmol/L). No matter when you last ate, a random blood sugar test of 200 mg/dL (11.1 mmol/L) or above suggests that you have diabetes. This is particularly true if you already have symptoms of diabetes.

A blood sugar level between 140 mg/dL (7.8 mmol/L) and 199 mg/dL (11.0 mmol/L) indicates prediabetes. A normal level is one that is less than 140 mg/dL (7.8 mmol/L).

Oral Glucose Tolerance Test

The oral glucose tolerance test also requires that you fast overnight. You will take a fasting blood sugar test. Then you will drink a sugary liquid. After you’re done, your blood sugar levels will be tested periodically for several hours. After two hours, a normal blood sugar level is less than 140 mg/dL (7.8 mmol/L). If after two hours you get a reading greater than 200 mg/dL (11.1 mmol/L) indicates you have diabetes. A reading between these levels indicates prediabetes. 

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

Getting a Second Opinion

You should always feel free to get a second opinion if you have any concerns or doubts about your diagnosis. Your health is exactly that — your health. Don’t feel intimidated. You have every right to a second opinion.

After You’ve Been Diagnosed

A diagnosis of diabetes is only the first step. Once you know you have diabetes, you have to take your health in hands. It’s important to follow through on all your monitoring and medical appointments. Getting your blood tested and tracking your symptoms are important steps to ensure long-term health.

You will have an array of doctors checking in on your health. But remember, you are ultimately responsible for your own well being. With diabetes, it’s possible to live a long, fulfilling life. It just requires a commitment to controlling your blood sugar and staying well. 

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