What is an ideal blood glucose level?

Updated July 19, 2017

Blood glucose level is a measurement of the sugar (glucose) content of blood. Throughout the day, blood glucose level fluctuates as you eat, drink, exercise, and sleep. Eating and drinking cause glucose levels to rise, and insulin lowers blood glucose levels. In a healthy individual, insulin is produced naturally by the pancreas. Somebody with diabetes may need to receive insulin through injections or inhalers to reduce glucose levels. Glucose levels also drop following exercise. Infections, illness, stress, and certain medicines also raise or lower glucose levels. Because glucose levels are constantly fluctuating, there is no single "ideal" level for blood glucose, but there are healthy blood glucose ranges.

Types of Tests

The two most common blood sugar tests are the simple finger-prick test and haemoglobin A1C. The simple finger-prick test measures the individual's glucose at that moment, and haemoglobin A1C gives an average glucose level for the preceding 2 to 3 months.

The finger-prick test measures glucose in milligrams (of glucose) per decilitre of blood (mg/dl). For diagnostic purposes, this is done when the individual has not eaten anything for 10 hours (fasting). People with diabetes also test immediately before a meal, or two hours after, to monitor ongoing glucose levels.

The A1C test requires a blood sample for laboratory analysis. Because glucose molecules stick to red blood cells--which live for 2 to 3 months--the A1C provides an average blood sugar level over the preceding 2 to 3 months.

Test Results

A healthy person's fasting blood glucose is between 75-100 mg/dl. A fasting level of 101-125 mg/dl indicates a glucose impairment (pre-diabetes), and 126 or higher indicates diabetes condition. A healthy, non-fasting blood glucose is between 80-120 mg/dl. Low blood sugar can also be a problem, and a level below 60 mg/dl is considered unhealthy.

A1C is measured on a scale of percentages up to 12%. A 5% A1C indicates an average glucose level of 90 mg/dl over the previous 2 to 3 months, while a 12% A1C is equivalent to 300 mg/dl. This test does not require the patient to fast, and the sample can be taken at any time.


To maintain the best health, maintain blood sugar in a healthy range with minimal extremes.A diabetic must know his glucose levels in order to determine the correct insulin dosage at a given time. If she does not take insulin, she should use it to maintain good control through diet, exercise and/or medication.


Maintaining a healthy blood glucose level is important for those with diabetes and pre-diabetes, as well as anyone who wants to maintain good overall health. Excess blood sugar triggers overproduction of insulin. That can lead to weight gain, complications from infections, high blood pressure, kidney disease, blindness, nervous system damage, amputation, heart disease, stroke, and dental disease.

Maintain Healthy Blood Glucose Levels

Regardless of current health, improve and maintain healthy glucose levels by following common-sense guidelines.

Maintain a healthy weight. Obesity is the single most important determining factor in developing Type 2 diabetes. As obesity rates rise, the number of diabetics increases.

Exercise regularly. Exercise reduces glucose levels immediately. It also increases insulin sensitivity, which is good for blood sugar in the long term. Get adequate amounts of sleep. How much--or how little--you sleep affects important hormones, such as choline and inositol. Those hormones get fat to your body's cells and help control your weight.

Eat a healthy diet. A variety of vegetables, fruits, proteins, whole grains, and undamaged fats in portion-controlled amounts are necessary for good health.

Balance is important. Don't eat all your fruits at one time, for example. Do eat carbohydrates and proteins together. Reduce or eliminate caffeine and alcohol.

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About the Author

Currently living in Central Florida, Susanna Perkins has been writing professionally for over 25 years. She has written for the Orlando and Rochester (NY) Business Journals, Orlando Magazine and other regional publications. She graduated from Middlebury College, Middlebury, Vt., with a degree in English, and cut her journalistic teeth with The Valley Voice, a weekly paper based in Middlebury.