According to the latest American Heart Association's Heart Disease and Stroke Statistics, about 8 million people 18 years and older in the United States have type 2 diabetes and do not know it. Often type 1 diabetes remains undiagnosed until symptoms become severe and hospitalization is required. Left untreated, diabetes can cause a number of health complications. That's why it's so important to both know what warning signs to look for and to see a health care provider regularly for routine wellness screenings.
In incidences of prediabetes, there are no symptoms. People may not be aware that they have type 1 or type 2 diabetes because they have no symptoms or because the symptoms are so mild that they go unnoticed for quite some time. However, some individuals do experience warning signs, so it's important to be familiar with them.
|Prediabetes||Type 1 Diabetes||Type 2 Diabetes|
|No symptoms||Increased or extreme thirst||Increased thirst|
| ||Increased appetite||Increased appetite|
| ||Increased fatigue||Fatigue|
| ||Increased or frequent urination||Increased urination, especially at night|
| ||Unusual weight loss||Weight loss|
| ||Blurred vision||Blurred vision|
| ||Fruity odor or breath||Sores that do not heal|
| ||In some cases, no symptoms||In some cases, no symptoms|
If you have any of these symptoms, see your health care provider right away. Diabetes can only be diagnosed by your healthcare provider.
Who should be tested for prediabetes and diabetes?
The U.S. Department of Health and Human Services recommends that you should be tested if you are:
- Overweight and over age 45
- Overweight, under age 45 and have one of more additional risk factors such as:
- High blood pressure
- High cholesterol
- A family history of diabetes
- African-American, Asian-American, Latino/Hispanic-American, Native American or Pacific Islander descent
- A history of gestational diabetes (diabetes during pregnancy) or delivering a baby over 9 lbs.
If your blood glucose levels are in normal range, testing should be done about every three years. If you have prediabetes, you should be checked for diabetes every one to two years after diagnosis.
Tests for Diagnosing Prediabetes and Diabetes
There are three types of tests that help health care providers make a diagnosis of prediabetes and diabetes.
HbA1C (A1C or glycosylated hemoglobin test) The A1C can be used for the diagnosis of both prediabetes and diabetes. The A1C test measures your average blood glucose control for the past 2 to 3 months. This test is more convenient because no fasting is required. An A1C of 5.7% to 6.4% means that you are at high risk for the development of diabetes and you have prediabetes. Diabetes is diagnosed when the A1C is 6.5% or higher.
Fasting Plasma Glucose Test (FPG) Oral Glucose Tolerance Test (OGTT)
Just prior to having this test run, the patient must fast (nothing to eat or drink except water) for eight hours. The health care provider draws blood from the patient. Then the plasma (the fluid part of the blood) is combined with other substances to determine the amount of glucose in the plasma, as measured in mg/dL. The chart below contains the FPG test's blood glucose ranges for prediabetes and diabetes and describes what each diagnosis means.
|Blood Glucose Range||Diagnosis||What It Means|
|100 to 125 mg/dL||Prediabetes (also called Impaired Fasting Glucose)||Blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes. This condition puts you at increased risk for developing type 2 diabetes, heart disease, and stroke.|
|126 mg/dL or more||Diabetes mellitus (type 2 diabetes)||Type 2 diabetes develops when your body doesn't make enough insulin or develops "insulin resistance" and can't make efficient use of the insulin it makes. It greatly increases your risk of heart disease and stroke.|
This test measures how well the body handles a standard amount of glucose. The health care provider draws the patient's blood before and two hours after the patient drinks a large, premeasured beverage containing glucose. Then, the doctor can compare the before-and-after glucose levels contained in the person's plasma to see how well the body processed the sugar. These levels are measured in mg/dL. The chart below contains the OGTT's blood glucose ranges for prediabetes and diabetes and describes what each diagnosis means.
|Blood Glucose Range||Diagnosis||What It Means|
|140 to 199 mg/dL||Prediabetes (also called Impaired Fasting Glucose)||Blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes. This condition puts you at increased risk for developing type 2 diabetes, heart disease, and stroke.|
|200 mg/dL or higher||Diabetes mellitus (type 2 diabetes)||Type 2 diabetes develops when your body doesn't make enough insulin or develops "insulin resistance" and can't make efficient use of the insulin it makes. It greatly increases your risk of heart disease and stroke.|
Tests for Monitoring Diabetes
Upon being diagnosed with diabetes, there are a couple of ways that patients can monitor their blood sugar level to see how well their treatment plan is working.
HbA1C (A1C or glycosylated hemoglobin test)
If diagnosed with type 2 diabetes, your health care provider may regularly run a test called HbA1c (A1C or glycosylated hemoglobin test). An A1C test provides a picture of your average blood sugar control for the past two to three months. Blood sugar is measured by the amount of glycosylated hemoglobin (A1C) in your blood.
There are a variety of easy-to-use home monitors on the market with which patients can test their blood sugar. If you are managing diabetes with the help of a home monitor, be sure to learn what results are too high and too low for you. Consult with your health care provider to learn what to do when your results are outside that target range.
Tests to Measure Heart Health
People with diabetes are at increased risk for a variety of health complications, including cardiovascular disease. Learn more about non-invasive and invasive tests doctors may order to check heart health.
This content was last reviewed August 2015.