What’s a Normal Blood Sugar?
I am often asked this question, “What is a normal blood sugar?” It should be relatively easy to answer, but there is a lot of potential confusion that I need to clarify.
What is the difference between sugar and glucose?
Sugar is the name for any one of many edible carbohydrates that taste sweet. The common one that you know is table sugar, which is actually sucrose, the sugar in sugar cane and sugar beets. Then there is the sugar in fruits, called fructose. But the sugar that really affects your life is glucose. This is the sugar that floats around in your blood, providing energy for your muscles, food for your brain cells and power for the millions of chemical reactions that take place in your body.
What is a normal blood glucose?
The American Diabetes Association and the U.S. Department of Health and Human Services have established levels of glucose that are considered normal and levels that establish a diagnosis of diabetes. These levels refer to the amount of glucose in the blood and are given in units called milligrams per deciliter (mg/dl). Most of the rest of the world uses International Units called millimoles per liter (mmol/L). You can transfer milligrams per deciliter into millimoles per liter by dividing the mg/dl by 18. For example, 126 mg/dl is equal to 7 mmol/L.
Here are the levels that these authorities have established:
- A normal blood glucose after an overnight fast is less than 100 mg/dl
- Diabetes is diagnosed when the blood glucose after an overnight fast is 126 mg/dl or greater on more than one occasion
- A normal blood glucose after a meal is up to 139 mg/dl
- Diabetes is diagnosed when the blood glucose after a meal is 200 mg/dl or greater on more than one occasion
That leaves a range of blood glucose from 100 to 125 mg/dl in the fasting state and 140 to 199 mg/dl in the fed state unaccounted for. If you have either one of those situations, you are considered to have prediabetes, a state that could turn into diabetes but may not depending on how you respond with weight loss and exercise.
What if your blood glucose is too low?
Symptoms associated with a low blood glucose usually begin around 60 mg/dl, but it is not the same for each person. It occurs when you are taking a medication to lower high blood glucose and you fail to eat, do too much exercise or take too much medication. Your body does everything it can to maintain a satisfactory level of blood glucose. If it goes too low, these are the symptoms of low blood glucose:
- You may get a headache
- You become confused and lose concentration
- You could go into a coma
- You become extremely weak
- You are extremely hungry
- You start to sweat
- Your heart beats fast
- You have numbness in your lips, fingers and toes
You can quickly reverse the low blood sugar by taking a little sugar, orange juice or honey.
What if your blood glucose is too high?
The treatment of diabetes is all about lowering the blood glucose so that it does not stay too high over ten or more years. If it remains too high for that long or longer you may get any or all of the following symptoms:
- Eye disease including blindness
- Kidney disease including kidney failure
- Nerve disease of many types
- Heart and blood vessel diseases including heart attacks, strokes poor blood flow to the legs
Usually, there are no symptoms of high blood glucose, so it is important to be screened with a blood glucose test at least once a year if you are 45 years of age or older.