Connect with others who understand.

sign up log in
Resources
About DiabetesTeam
Powered By

Diabetes – The Path to Diagnosis

Updated on October 18, 2021
Medically reviewed by
Robert Hurd, M.D.
Article written by
Kelly Crumrin

Type 2 diabetes is easy to diagnose once someone gets tested for it. As many as one-third of people with type 2 diabetes do not know they have the disease. Early on, diabetes symptoms are mild and may be easily confused with other conditions or signs of aging.

Type 2 diabetes is most commonly diagnosed in people age 45 or older, but younger adults and even children can develop type 2 diabetes too. Routine testing is recommended for people who:

  • Are age 45 or older
  • Are between the ages of 19 and 44, and overweight or obese
  • Are between the ages of 10 and 18, overweight or obese, with additional risk factors such as family history of diabetes or low birth weight
  • Had gestational diabetes while pregnant
  • Are currently pregnant

Most people are diagnosed with diabetes by their primary care physician or family doctor. Your general practitioner may continue to treat your diabetes, or they may refer you to an endocrinologist. Endocrinologists specialize in diseases of the glands and hormone imbalance — diabetes involves problems with the pancreas, a gland that produces the hormone insulin. Read more about causes of diabetes.

How Is Type 2 Diabetes Diagnosed?

The doctor will draw a small blood sample to test your blood glucose level. In people with type 2 diabetes, cells become resistant to insulin. Insulin is the hormone necessary to allow cells to take in glucose from the bloodstream and regulate how much glucose remains in your blood. As diabetes progresses, cells can take in less and less glucose, and blood glucose levels rise.

There are several ways of testing blood glucose. The doctor will likely repeat the blood test on another day soon after to make sure the diagnosis is correct.

A1C

The results of the A1C test, also referred to as HbA1c, glycated hemoglobin, or glycohemoglobin test, show your average blood glucose over the past two to three months. A1C is used to diagnose type 2 diabetes and to monitor how well blood glucose is being managed in people taking treatments for type 2 diabetes.

A1C is expressed as a percentage.

  • Less than 5.7 percent is considered normal.
  • 5.7 percent to 6.4 percent indicates prediabetes.
  • 6.5 percent or higher indicates diabetes.

Oral Glucose Tolerance Test (OGTT)

For the OGTT, the doctor will take a blood sample, then provide a sweet beverage with a high glucose content. After waiting two hours, another blood sample will be taken to check how your blood glucose level has risen in response to the drink.

OGTT results are expressed in milligrams of glucose per deciliter of blood (often written as mg/dL).

  • Less than 100 milligrams per deciliter after an eight-hour fast is considered normal.
  • 100 to 125 milligrams per deciliter indicates prediabetes.
  • 126 milligrams per deciliter or higher indicates diabetes.

Fasting Plasma Glucose (FPG)

A fasting plasma glucose test is usually scheduled early in the morning. For an accurate result, you should fast — not eat or drink anything but water — for at least eight hours before the blood sample is taken.

Results are expressed in milligrams of glucose per deciliter, and diagnostic ranges are the same as for the oral tolerance test.

Random Plasma Glucose Test

A blood sample for a random or casual blood glucose test can be taken at any time. Results are expressed in miligrams per deciliter. A test result of 200 milligrams per deciliter or higher indicates diabetes. Any test would need to be repeated to confirm the diagnosis of type 2 diabetes.

Condition Guide

References

  1. Diabetes — Mayo Clinic
  2. Diagnosing Diabetes and Learning About Prediabetes — American Diabetes Association
  3. Diabetes Tests & Diagnosis — National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center

Updated on October 18, 2021
All updates must be accompanied by text or a picture.
Robert Hurd, M.D. is a professor of endocrinology and health care ethics at Xavier University. Review provided by VeriMed Healthcare Network. Learn more about him here.
Kelly Crumrin is a senior editor at MyHealthTeam and leads the creation of content that educates and empowers people with chronic illnesses. Learn more about her here.

Related articles

When a person becomes pregnant, they may develop a temporary form of diabetes called gestational ...

Gestational Diabetes: Pathophysiology, Symptoms, and More

When a person becomes pregnant, they may develop a temporary form of diabetes called gestational ...
As someone living with type 2 diabetes mellitus, you have probably experienced common symptoms l...

Yeast Infections and Diabetes

As someone living with type 2 diabetes mellitus, you have probably experienced common symptoms l...
The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...

What People With Diabetes Should Know About Getting a Second COVID-19 Booster Shot

The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...
Many members of DiabetesTeam have wondered about how magnesium levels relate to diabetes. One me...

Magnesium for Diabetes: Does It Help?

Many members of DiabetesTeam have wondered about how magnesium levels relate to diabetes. One me...
There are several types of diabetes. Most forms of diabetes are chronic — lasting throughout lif...

Types of Diabetes

There are several types of diabetes. Most forms of diabetes are chronic — lasting throughout lif...
Type 2 diabetes is a chronic disease in which your body is unable to regulate the levels of gluc...

Type 2 Diabetes – An Overview

Type 2 diabetes is a chronic disease in which your body is unable to regulate the levels of gluc...

Recent articles

If you’re living with type 2 diabetes (also known as diabetes mellitus), you understand how impor...

Hypoglycemia vs. Hyperglycemia: 5 Not-So-Obvious Differences

If you’re living with type 2 diabetes (also known as diabetes mellitus), you understand how impor...
There are several strategies to prevent type 2 diabetes, but reversing the condition after you ha...

Can You Reverse Type 2 Diabetes? FAQs on Diet and Lifestyle Changes

There are several strategies to prevent type 2 diabetes, but reversing the condition after you ha...
Cinnamon has attracted a great deal of interest for its potential role in lowering blood sugar le...

Cinnamon and Diabetes: Can It Help?

Cinnamon has attracted a great deal of interest for its potential role in lowering blood sugar le...
Healthy eating is a crucial part of controlling blood sugar if you have type 2 diabetes, and nutr...

Can You Drink Orange Juice if You Have Diabetes?

Healthy eating is a crucial part of controlling blood sugar if you have type 2 diabetes, and nutr...
Although some lifestyle recommendations stand true for pretty much everyone with diabetes, coffee...

Coffee and Diabetes: 5 Safety and Blood Sugar Questions Answered

Although some lifestyle recommendations stand true for pretty much everyone with diabetes, coffee...
Some people living with diabetes wonder whether they should wear medical alert jewelry, a form of...

Diabetes Medical Alert Bracelets: What To Engrave on Yours

Some people living with diabetes wonder whether they should wear medical alert jewelry, a form of...
DiabetesTeam My diabetes Team

Thank you for subscribing!

Become a member to get even more:

sign up for free

close