The term "blood sugar" describes the presence of a simple sugar called glucose in the bloodstream. "Average blood sugar" is a term that most commonly refers to the percentage of red blood cells that have been in contact with glucose molecules in the prior few months. When a glucose molecule binds to a red blood cell, it permanently alters that red blood cell, which is detectable by an A1C test. Obtaining an A1C test is most pertinent if you have been diagnosed with diabetes mellitus, in order to evaluate the effectiveness of treatment through the observation of blood glucose levels over several months.
Though an A1C is normally used to obtain average blood sugar readings, you can detect your blood sugar levels at home with a glucose meter. This test involves pricking your finger to obtain a blood sample. You then deposit the blood sample on a test strip and insert that test strip into the glucose meter for detection. You can get your average blood sugar by taking random readings throughout the day and averaging those readings. To determine an average, add the values of all of the samples and divide the total by the number of samples taken.
In a healthy individual, glucose is obtained by eating starchy foods, and that glucose is absorbed into the bloodstream and then facilitated into the body’s cells by the insulin hormone. Glucose serves as the cells’ source of energy and is critical for cellular function. The amount of insulin released depends on the amount of glucose in the blood, and this release occurs almost immediately after glucose levels start rising. This quick response ensures that glucose levels do not fluctuate out of their normal range and therefore, average blood sugar readings should be steady.
If you suffer from diabetes mellitus, your body does not properly control your blood sugar, so it will fluctuate greatly throughout the day. After a meal, glucose obtained from the meal will build up in your bloodstream and will cause your average blood sugar readings to be greater than normal. This is referred to as high blood sugar. If your high blood sugar is persistent and left untreated, several complications can arise, including blindness, stroke, heart attack, high blood pressure and wounds resistant to healing.
If your blood sugar in these cases has not been replenished by eating, you will have a low average blood sugar. If your blood sugar gets too low, your body will begin to shut down because of lack of fuel, and you risk going into a coma, known as a diabetic coma. This is a critical condition that, if left untreated, will result in death.