What is a healthy blood sugar level?

According to the American Diabetes Association, normal blood glucose ranges between 70 to 99 milligrams per deciliter (mg/dL).

Having a high blood sugar level can mean you have diabetes. Watch as Dr. Oz explains what a healthy reading is in this video.

A healthy blood sugar level is between 70 and 130 milligrams per deciliter (mg/dL) before meals and less than 180 mg/dL one to two hours after the start of a meal, according to the American Diabetes Association. Three tests are commonly used to measure blood sugar levels. A random plasma glucose test is a blood test that is done at any time of day. It may indicate you have diabetes if your blood glucose level is 200 mg/dL or higher. A fasting plasma glucose (FPG) test is often done first thing in the morning, after you have not eaten for at least eight hours. You may be diagnosed with prediabetes (at risk for diabetes) if your blood glucose level is 100 to 125 mg/dL on the FPG test, and you may have diabetes if your level is 126 mg/dL or higher.

The third test, called the oral glucose tolerance test, (OGTT) is also done after you have fasted for eight hours. You'll consume a glucose-containing beverage, and your blood will be taken two hours later. If your blood glucose level measures 200 mg/dL or higher on two different OGTTs, you may be diagnosed with diabetes. If it measures 140 to 199 on an OGTT, you may have prediabetes.

In a person without diabetes, the body keeps its blood-glucose level between meals in a range of about 70 to 99 milligrams per deciliter (mg/dL). This level will rise after eating, depending on the type and amount of food consumed, but it will not exceed 139 mg/dL. It also quickly returns to the between-meal range.

A healthy blood sugar level, obtained in a fasting state, is less than 100. A fasting blood sugar of greater than 126 is diabetic. A fasting blood sugar between 100 and 126 is considered "prediabetic." Prediabetes can be associated with increased risk for heart disease and should lead to lifestyle changes.

For people without diabetes, blood glucose levels rarely go over 120 mg/dl, even after eating a meal.

People with diabetes need to take action to lower their blood glucose either by injecting insulin or compensating with food or insulin at the next mealtime. You may hear that keeping your blood glucose below 130 mg/dl is the magic number. In fact, your target range may be a little higher or lower depending on several factors such as your age, capabilities, and life situation.