The Diabetes Test Guide

The Diabetes Test Summary
What: Testing to either determine or monitor diabetes.
Who: These tests are for patients with a diagnosis of diabetes or patients who may be diabetic.
Where: Diabetic testing can occur in the medical laboratory or in the home.
When: While testing is requested at periodic intervals by a physician to monitor blood sugar levels, home testing by diabetic patients is done 4-6 times per day.
How: Blood is drawn from the patient by either the patient themselves or at a medical facility. The blood sample is then tested via a chemical reaction to measure the amount of glucose in the bloodstream.
Type: Diabetes patients most commonly use blood glucose meters for home testing of their blood sugar levels. Physicians have a battery of tests available to diagnose and monitor a patient.
Why: Blood glucose testing is used to both diagnose and monitor blood sugar levels in patients.
Time: Varies.
Language: N/A
Preparation: The frequency and preparation of home blood glucose level testing will be determined by the patient's physician.
Cost: The costs of home blood glucose testing are comprised of the cost for the meter, reagent strips to test the blood and lancets to pierce the skin. These costs may or may not be covered by health insurance. The costs of blood sugar testing as requested by a

By Mary Kay Radnich, Tests.com Contributing Writer

Diabetes is a serious disease resulting when the body is unable to absorb glucose, the form of sugar that the body uses for fuel. Insulin, a hormone produced by the pancreas, is needed for the body to absorb glucose into cells to be used for energy and growth. When insulin production is insufficient, glucose cells are left in the bloodstream and excreted thru the urine, leaving the body without an energy source.

Symptoms of diabetes may include frequent urination, excessive thirst, excessive hunger, unusual weight loss, increased fatigue, irritability or blurry vision.

Left untreated, diabetes can cause nerve damage (diabetic neuropathy), poor vision or blindness (diabetic retinopathy), heart disease, high blood pressure, depression and even death.

There are three types of diabetes. Type 1, or juvenile, diabetes is an auto-immune disorder, which means that the immune system attacks the pancreatic cells, thereby causing the pancreas to not produce insulin, which is necessary for cells to produce energy. According to the American Diabetes Association, approximately 5-10% of Americans have Type 1 diabetes.

Type 2 diabetes, formerly known as adult-onset diabetes, occurs when the body becomes resistant to insulin over time. This insulin-resistant type of diabetes occurs in the majority of Americans diagnosed with diabetes.

Gestational diabetes occurs during pregnancy. Approximately 5-10% of these women are diagnosed as being diabetic right after their babies are delivered.

Types of Diabetes Tests

If a physician suspects that a patient has diabetes, they will order a variety of tests to determine if the body is producing sufficient quantities of insulin.

Blood sugar testing is the primary method of diagnosing and monitoring diabetes. Blood sugar levels are measured by taking a sample of blood, either at home with a blood glucose meter or by a medical technician and sent to a lab for analysis. The blood sample is used in a chemical reaction and the results measure the level of glucose in the blood.

Diabetes tests may include any or all of the following:

Fasting Plasma Glucose Test: After an 8 hour fast, blood will be drawn and sent to a lab for analysis. Blood glucose in the range of 70-100 mg/liter is considered normal. Two test results with blood sugar levels measuring over 126 mg/liter will result in a diagnoses of diabetes.

Casual Plasma Glucose Test: Blood is drawn without regard to time or previous meals and sent to a lab, to see if the blood glucose level is over 200mg/liter.

Oral Glucose Tolerance Test: This is a test to measure how quickly the body absorbs a sweet glucose solution that the patient drinks quickly. A blood sample is taken before the glucose solution is consumed and then at specific time intervals afterwards, up to 4 hours. This test is commonly used to diagnose gestational diabetes.

Hemoglobin A1c Test (Glycated Hemoglobin Test): Hemoglobin A1c is a component of hemoglobin to which glucose or blood sugar molecules can bind. This blood test measures how long glucose molecules are bound to the A1c component over a period of 3-4 months. A high reading can indicate the presence of diabetes. In a diagnosed diabetic patient, the results show the range of the blood sugar readings over the same period of time.

Once an individual is diagnosed with any form of diabetes, regular testing of blood sugar levels must be performed several times daily to help prevent or delay the onset of serious consequences of the disease. Daily monitoring of diabetes is easily accomplished now using blood glucose meters which measure the glycemic index of the blood. The results are instant and accurate, making them very convenient for self-monitoring of blood sugar levels throughout the day. A variety of meters are available for purchase. A physician will determine the frequency of use for a blood glucose meter and how to interpret the results, so that the patient can achieve a high quality of life in the face of this serious disease.

Preparation for Testing

The casual glucose test does not require any special preparation. The fasting plasma glucose test, the oral glucose tolerance test and the hemoglobin A1c test each require an eight-hour or overnight fast in preparation for the blood to be sampled. While no particular preparation is required for using a blood glucose meter, a physician may provide a patient with an individualized schedule of when to test their blood and what each test result will mean.


The risks involved with diabetic testing are quite low. Patients should be sure that the site from which blood is drawn is cleaned with alcohol and that the implement used to draw blood is sterile to prevent infection.

Do you suspect you have diabetes and need to find a doctor for testing? Have you already been diagnosed with diabetes and want to purchase a blood glucose meter for use at home? Please consult our Diabetes Test Directory for a list of providers who may meet your diabetes testing needs.