The American Diabetes Association estimates that 1.6 million Americans are diagnosed with diabetes each year. Diabetes is a complex illness that affects many aspects of a person's health, but it is easy to diagnose.
There are two types of diabetes. Type 1 diabetes occurs when the body is unable to make insulin. In Type 2 diabetes, the body either doesn't make enough insulin or is unable to use the insulin it does produce. Insulin is a hormone that helps the cells of the body take in sugar, or glucose, that is circulating in the blood stream and use it for energy.
Tests for Diabetes
Since diabetes hinders the body's ability to use sugar, more sugar is left circulating in the blood stream. Doctors diagnose diabetes using a blood glucose test. A blood sample is drawn and the concentration of sugar in the plasma of the blood is analyzed in a lab.
Most doctors prefer to test for diabetes after the patient has fasted overnight. A fasting plasma glucose level above 126 mg/dL (milligrams per deciliter) suggests diabetes. Diabetes is diagnosed when a patient has had two fasting blood glucose tests above 126 mg/dL on two different days. One high blood sugar test is not enough to diagnose someone with diabetes especially if the person has no other symptoms.
A doctor may also do an oral glucose tolerance test. In this test a person fasts overnight and then drinks a solution containing 75 grams of glucose. Two hours later blood is drawn. Blood glucose above 200 mg/dL after a glucose tolerance test denotes diabetes.
Symptoms of Diabetes
The first symptoms of type 1 diabetes are frequent urination, increased thirst and excessive hunger. Often, a child who had outgrown wetting accidents may begin having them again at the onset of diabetes. Other symptoms of type 1 diabetes are weight loss, fatigue and irritability.
The symptoms of type 2 diabetes include all the symptoms of type 1 diabetes, with the addition of frequent infections, blurred vision, difficulty healing from cuts or bruises and tingling or numbness in the hands and feet. Some people with type 2 diabetes do not have any symptoms other than elevated blood sugar.
The A1c Test
The A1c, or hemoglobin A1c assay test, measures a person's blood glucose over time by taking the percentage of glycated hemoglobin. Hemoglobin is the protein in the red blood cells that carries oxygen through the body. When it is exposed to glucose in the blood, hemoglobin reacts and permanently changes to the glycated form. Since red blood cells live for 120 days, measuring the glycated hemoglobin gives the physician a picture of the blood glucose concentration over a longer period of time. The A1c in a person without diabetes is 5 percent. The ADA recommends that diabetics aim for an A1c below 7 percent.
The A1c is primarily used as a measure of glucose control in people already diagnosed with diabetes. In 2008, however, an International Expert Committee urged physicians to begin using the A1c test to diagnose diabetes. As of 2009, the ADA still recommended the fasting glucose test for diabetes diagnosis.
