Your blood naturally contains a certain amount of a sugar known as glucose. Glucose is the predominant fuel for cells within the body. High blood glucose levels can be a sign of diabetes, a condition caused by problems with how your body produces or responds to insulin. Thus, the amount of glucose in your blood can be used to diagnose or monitor diabetes.
Types
There are many different kinds of blood glucose tests. The basic blood glucose test can be elevated by eating, as your blood glucose levels naturally rise after a meal, LabTestsOnline explains. Thus, a more accurate measure of your body's blood glucose is your fasting blood glucose, which is measured when you have not eaten for several hours. After your fasting blood glucose levels are measured, you can also receive an oral glucose tolerance test, in which you are given a set amount of carbohydrate to measure its effects on your blood glucose level.
Normal Levels
Fasting blood glucose levels are typically used to screen for diabetes. A normal fasting blood glucose is between 70 and 99 mg per dL of blood, LabTestsOnline reports. Impaired fasting glucose, which can be classified as pre-diabetes, yields levels between 100 and 125 mg per dL. If you have diabetes, your blood glucose levels may be above 125 mg per dL. After an oral glucose tolerance test, normal blood glucose levels are below 140 mg per dL; levels between 140 and 200 mg per dL are indicative of pre-diabetes and anything above this could signify the onset of diabetes.
Hemoglobin A1c
Another test that can be used to indirectly measure your blood glucose levels is the hemoglobin A1c test. Hemoglobin is a protein your red blood cells use to transport oxygen. When hemoglobin is exposed to glucose, it gets converted into hemoglobin A1c. Because hemoglobin molecules are recycled every few months, the percentage of your hemoglobin in the A1c form can be used as a measurement of your average blood glucose levels over the past three months. Normal hemoglobin A1c levels are less than 7 percent, the American Diabetes Association notes.
Hypoglycemia
Hypoglycemia occurs when your blood glucose levels dip below 70 mg per dL, which is abnormally low, PubMed Health states. Hypoglycemia can be dangerous and lead to confusion, cold sweats, vision problems, headache, trembling, convulsions and a fever, as well as fainting or a coma. Abnormally low blood glucose levels can be caused by eating too little food or taking too much insulin. If you have hypoglycemia, you will need to ingest carbohydrates to bring your blood glucose levels up to normal.
