Can You Have Prediabetes and Not Know It? | Get Healthy Stay Healthy

Can You Have Prediabetes and Not Know It?

Published on Nov 09, 2018
Authored by Pfizer Medical Team

While you have probably heard of diabetes, you may not be as familiar with the medical condition known as prediabetes. A person is said to have prediabetes when their blood sugar levels are higher than normal, but not high enough to be diagnosed with type 2 diabetes.

Studies have shown that most people with prediabetes develop type 2 diabetes within 10 years unless they take steps toward a healthier lifestyle. And having type 2 diabetes can lead to a number of serious health problems, including kidney failure, blindness, and damage to nerves and blood vessels can result in amputation of a toe, foot, or leg. Learn more about prediabetes, its risk factors, and the steps you can take to help prevent it.

What causes high blood sugar?

A hormone in the body, called insulin, plays a key role in how the body uses glucose (a form of sugar we get from digested food) for energy. Insulin is made in an organ called the pancreas and is released into the bloodstream after we eat. When certain cells in the body cannot absorb glucose as easily (called insulin resistance), there is a buildup of sugar in the blood. Over time, this causes the pancreas to make more and more insulin as it tries to get the cells to respond the way they should. Eventually the pancreas can’t keep up and blood sugar levels rise. Eventually, this can lead to prediabetes and type 2 diabetes.

Researchers believe that being overweight and a lack of physical activity are among the leading causes of insulin resistance. Some other causes of insulin resistance may include taking certain medications, steroid use, hormones, issues with sleep (such as sleep apnoea), smoking, and older age.

Are you at risk for prediabetes?

Because prediabetes often has no signs or symptoms, many people don’t know they have it. However, there are a number of risk factors that increase the chances for developing it.

To find out if you are at risk for prediabetes, take a look at the statements below. If you have one or more risk factors, talk with your GP about testing. He or she can order a simple blood test to confirm it.

  • I am overweight.
  • I have a parent, brother, or sister who has type 2 diabetes.
  • I am physically active fewer than 3 times a week.
  • I have a history of cardiovascular disease, high blood pressure, high triglycerides, or low HDL.  
  • I have given birth to a baby that weighed more than 4.5 kgs or I have had diabetes during pregnancy (gestational diabetes).
  • I have polycystic ovary syndrome (PCOS).
  • I come from an Aboriginal or Torres Strait Islander background.
  • I come from a Pacific Islander, South-East Asian or Indian background.

How do you diagnose prediabetes?

Since prediabetes generally has no signs or symptoms, diagnosis is generally based on the following blood tests:

  • Fasting Plasma Glucose (FPG) test: Measures blood glucose in a person who has fasted (nothing to eat or drink except water) for at least 8 hours before the test. Prediabetes is diagnosed when the fasting blood glucose level is 6.1 to 6.9 mmol/L.
  • Oral Glucose Tolerance Test (OGTT): Measures blood glucose in a person 2 hours after drinking a liquid containing glucose dissolved in water. Prediabetes is diagnosed when the blood glucose level is 7.8 to 11 mmol/L 2 hours after drinking the liquid with glucose in it.

Questions to ask your GP about prediabetes

Below are questions you can ask your GP about your risk for prediabetes.

  • If I have prediabetes, how likely will I be to get type 2 diabetes?
  • What is the most important step I can take to avoid developing type 2 diabetes?
  • My parent or sibling has diabetes. How often should I be screened for prediabetes?
  • If I have diabetes, should I have my children screened for prediabetes?
  • If I had gestational diabetes (diabetes that develops during pregnancy), how often should I be screened for prediabetes?
  • Is there a specific diet I should follow that will help me avoid developing prediabetes?
  • Should I talk with a dietitian about changing what I eat?

What you can do to prevent type 2 diabetes

If you have been diagnosed with prediabetes, it is important to work with your GP to improve your lifestyle habits. These lifestyle changes may help reduce your chances of developing type 2 diabetes. Key changes include:

  • Losing weight, if you are overweight. For many people, losing 5% to 7% of their body weight can make a big difference. That’s 4.5 to 6.3 kg for a 90 kg person.
  • Making physical activity a regular part of your life. For example, try to walk at a brisk pace for at least 30 minutes on most days, if not every day of the week Eating a healthy diet that consists of fruits, vegetables, whole grains, and meats. Try to avoid processed foods.

Medically reviewed by Lisa Tarasenko, PharmD, MBA, Senior Director, Pfizer.

[1] [2] [3]


  • 1. Diabetes Management [revised July 2018].In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited. Accessed 17/10/2018
  • 2. Diabetes: Detection and Diagnosis [revised July 2018].In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited. Accessed 17/10/2018
  • 3. National Institute of Diabetes and Digestive and Kidney Diseases. Prediabetes & Insulin Resistance. Accessed March 13, 2018.
External Resources

Quick Poll

After reading this article, how likely are you to work with your GP to take steps to help prevent or manage prediabetes?