What is Prediabetes? Definition and Symptoms
Prediabetes is a condition that you might not even know you have but is very important to pay attention to and manage to prevent full-blown diabetes.
Definition of Prediabetes
You may already know that there are three primary types of diabetes—type 1, type 2, and gestational—but what is prediabetes? A simple prediabetes definition is this: it’s not a disease, nor is it a type of diabetes; instead, prediabetes is a warning sign that your metabolism is off and that you’re at risk for developing type 2 diabetes.
When your body is diabetes-free, it is able to properly metabolize sugar into energy. When you eat carbohydrates, they break down into glucose (sugar) during digestion. Then, a hormone called insulin leads the glucose out of the bloodstream and into the cells. This process is called metabolism and gives cells the energy they need to function plus keeps glucose out of the bloodstream. Excess glucose in the bloodstream can lead to significant health problems.
In diabetes, the process goes awry because your body either can’t produce insulin (type 1 diabetes) or can’t use it efficiently (type 2 diabetes). In both cases, blood glucose levels remain dangerously high (hyperglycemia) without treatment.
Type 2 diabetes doesn’t develop overnight but instead builds gradually. The period in which blood glucose levels are climbing toward diabetic levels is considered prediabetes, also called impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). Prediabetes isn’t diabetes, but it’s a condition in which someone’s blood sugar levels are higher than normal but not yet high enough for type 2 diabetes. Understanding what prediabetes is can help you avoid and possibly even reverse it before it becomes type 2 diabetes.
Prediabetes Symptoms, Signs, and Risk Factors
If clear prediabetes symptoms and signs existed, it would be fairly easy to identify when your blood glucose levels were rising and then take action to return your metabolism to normal functioning. Unfortunately, in most cases, there are no signs or symptoms of prediabetes.
There is one possible sign that can appear. Some people with prediabetes will develop acanthosis—darkened skin on some parts of their body, usually the neck, armpits, knuckles, elbows, and knees. But in the majority of cases, prediabetes has no obvious signs or symptoms, which means that many people who have prediabetes don’t even know it.
While there are no symptoms of prediabetes, there are numerous risk factors. The presence of these risk factors could signify that someone might have prediabetes. These include:
- Obesity or overweight (fatty tissue makes the body more resistant to insulin)
- Waist size of over 40 inches in men and 35 in women (like weight, this can cause insulin resistance)
- Diet high in processed foods, sugary drinks, and red meat
- Sedentary lifestyle
- Prior gestational diabetes
- Age (diabetes risk increases over the age of 40)
- Family history of type 2
Certain medical conditions increase someone’s risk for prediabetes and, eventually, type 2 diabetes. Examples of such conditions:
- Obstructive sleep apnea or working nights or swinging shifts (all contribute to insulin resistance)
- Polycystic ovary syndrome
- High blood pressure
- Low levels of good cholesterol (HDL)
- High levels of triglycerides (fat in the bloodstream)
- Metabolic syndrome (at least three of these: high blood pressure, low HDL levels, high triglycerides, and obesity)
Due to the lack of symptoms, people often discover that they have prediabetes by accident. When they visit the doctor for something else, the doctor may suspect prediabetes and order tests. A doctor’s suspicion comes from the above risk factors. The more someone has, the higher the likelihood that he or she has prediabetes. If you have some of the risk factors, you don’t have to wait for a doctor to investigate your health. You can make an appointment to check for prediabetes because there are tests for the condition.
Doctors choose one of three tests to check for prediabetes:
- Oral glucose tolerance test
- Fasting blood sugar levels test
- Hemoglobin A1c test
Each test is a slightly different measurement of blood glucose. If your level is higher than a normal blood glucose level but lower than what is required for a diabetes diagnosis, you will fit the criteria for prediabetes ("How to Diagnose Diabetes: Criteria, Tests for Diabetes Diagnosis").
If you have prediabetes, you aren’t doomed to develop diabetes. By managing certain aspects of your lifestyle, you can lower your blood sugar levels and reverse the condition. Many prediabetes treatment options exist, all of which involve addressing the above risk factors.
Perhaps the best way to treat prediabetes is to lose weight, eat nutritiously, and exercise. This will impact some of the other risk factors. The more areas you improve, the better your chances will be of returning blood sugar levels to normal and avoiding type 2 diabetes.
Another good prediabetes definition is that prediabetes is a chance to develop a healthier lifestyle, feel great, and reduce your risk of diabetes.
Last Updated: 09 January 2019
Reviewed by Harry Croft, MD