Symptoms And Diagnosis Of Diabetes
Common symptoms of diabetes include increased thirst and urination, unusual weight changes, irritability, fatigue, and blurry vision. Clinical abnormalities include hyperglycemia and glucose in the urine. The breath might smell sweet because of ketones in the blood (ketosis), which are naturally sweet smelling. Dark outgrowths of skin (skin tags) may also appear.
The most common clinical tests used to diagnose diabetes are measures of blood glucose. The fasting plasma glucose (FPG) test measures the amount of glucose in the blood after fasting. Prediabetes is diagnosed if the fasting blood glucose level is between 100 and 125 mg/dL. Diabetes is diagnosed if the fasting blood glucose level rises to 126 mg/dL or above.
The oral glucose tolerance test (OGTT) is used to measure insulin response to high glucose levels. During this test, patients are given glucose, and the rise in blood glucose levels is measured. Prediabetes is diagnosed if the glucose level rises to between 140 and 199 mg/dL. Diabetes is diagnosed if blood glucose levels rise to 200 mg/dL or higher.
The HbA1c test is also helpful in diagnosing less severe cases of diabetes. From this test, clinicians can estimate the average blood glucose level during the preceding two to four months. Normally 4 to 6 percent of hemoglobin is glycosylated, which corresponds to average blood glucose between 60 and 120 mg/dL. Mild hyperglycemia increases HbA1c to 8 to 10 percent (or 180 to 240 mg/dL), while severe hyperglycemia increases HbA1c values up to 20 percent. For diabetics, a healthy HbA1c level is less than 7 percent, which corresponds to an average blood glucose level of 150 mg/dL or less.