What is a normal blood sugar level?
The answer to the question what is a normal blood sugar level is as follows:
Fasting normal blood sugar
Normal for person without diabetes: 70–99 mg/dl (3.9–5.5 mmol/L)
Official ADA recommendation for someone with diabetes: 80–130 mg/dl (4.4–7.2 mmol/L)
Normal blood sugar 2 hours after meals
Normal for person without diabetes: Less than 140 mg/dl (7.8 mmol/L)
Official ADA recommendation for someone with diabetes: Less than 180 mg/dl (10.0 mmol/L)
Normal for person without diabetes: Less than 5.7%
Official ADA recommendation for someone with diabetes: Less than 7.0%
Source: American Diabetes Association
Blood sugar levels and diabetes
If you have diabetes, you may be wondering (or, have wondered at some point) what your blood glucose (sugar) “should” be. Hopefully your doctor, nurse practitioner, physician’s assistant or whoever diagnosed you has given you answers to that question. Unfortunately, though, not everyone is given glucose goals. Or in some cases, it may have been a long time ago, and they’ve since been forgotten. No worries — we’ll go over all that!
What is blood glucose, anyway?
Blood glucose, or sugar, is sugar that is in your blood (easy enough!). It comes from the food that you eat — foods that contain carbohydrate, such as bread, pasta and fruit are the main contributors to blood glucose. The cells in our bodies need glucose for energy — and we all need energy to move, think, learn and breathe. The brain, which is the command center, uses about half of all the energy from glucose in the body.
When things go awry
When we eat food, the pancreas (an organ that sits between the stomach and the spine) goes to work, releasing enzymes that help to break down food and hormones that help the body handle the influx of glucose. One of these hormones is insulin, and it plays a key role in managing glucose levels in the blood.
And here is where things can go wrong. If the pancreas doesn’t make enough insulin — or stops making it altogether, in the case of type 1 diabetes — glucose levels in the blood can rise too high. Another scenario is that the pancreas makes enough insulin but the cells have trouble using it properly, causing blood glucose levels to rise. This is called insulin resistance and is the hallmark of type 2 diabetes.
In the short term, high blood glucose levels can make you feel downright bad. Thirst, frequent trips to the bathroom, fatigue and weight loss are all symptoms of high blood glucose (hyperglycemia). If not treated, more serious issues can occur, such as diabetic ketoacidosis. Chronic high blood glucose levels can lead to complications such as heart, kidney and eye disease, as well as nerve damage. So, it’s all about the blood glucose.
How do you know what your blood glucose level is?
For the most part, you can’t “feel” what your blood glucose level is — unless it’s fairly high or it’s low. You may not even always have symptoms of either high or low blood glucose; in fact, many people with type 2 diabetes don’t have the usual symptoms of high blood glucose, and for this reason, it’s not uncommon for people to go undiagnosed for many years.
The best way to know your blood glucose level is to check it with a glucose meter. This means doing a fingerstick with a lancet and getting a drop of blood onto a test strip, then inserting the strip into the meter for a reading. Your doctor may be able to give you a meter free of charge, but you’ll likely need to pay for test strips and lancets. But check with your health plan, as there are likely one or two “preferred” meters that they want you to use.
Another way to know what your glucose levels are up to is to use a continuous glucose monitor, or CGM, which reads glucose in the interstitial fluid (the fluid between cells) about every 5 minutes. Continuous glucose monitoring is expensive and may or may not be covered by your health plan.
Now that you’re checking your blood glucose, what do the numbers mean?
Depending on your diabetes treatment plan, your doctor or diabetes educator may advise you to check once a week, once a day or up to 10 times a day (hint: if they don’t tell you, ask!). But what does it mean when you see a 67, 101 or 350 on your meter? And what is a “normal” blood sugar, anyway? Great questions! After all, if you don’t know what the numbers on your meter mean, it’s hard to know how you’re doing.
(Here’s where the term “normal” comes in. According to the Merriam-Webster dictionary, one definition of normal is “conforming to a type, standard, or regular pattern.” It’s a term that not everyone takes kindly to, because if you’re not “normal,” you might be considered “abnormal,” which means, “unusual in an unwelcome or problematic way.” Rather than thinking of your blood sugars as being normal or abnormal, you might think of them as being “in range,” “in target” or “at goal.”)
The American Diabetes Association (ADA) provides guidelines (not mandates) for blood glucose goals for people with diabetes, and the goals vary depending on when you’re checking your glucose:
• Fasting (before eating the first meal of the day) and before meals: 80–130 mg/dl (4.4–7.2 mmol/L)
• Postprandial (one to two hours after a meal): Less than 180 mg/dl (10.0 mmol/L)
By the way, these guidelines are for non-pregnant adults with type 1 or type 2 diabetes. Children, adolescents and pregnant women may have different goals.
Your blood glucose goals may be different, however. If you’re younger, have had diabetes for a shorter amount of time or are not taking any medicine for your diabetes, your glucose goals might be a little “tighter,” or lower. Likewise, your blood glucose goals may be higher than what ADA recommends if you’re older, have diabetes complications, or don’t get symptoms when your blood glucose is low.
Bottom line: talk with your health-care provider about the following:
• When to check your blood glucose
• How often to check your blood glucose
• What your blood glucose goals are (don’t forget to ask about your A1C goal, as well)
Know your numbers
Consider keeping a log of your glucose levels. You can use good old-fashioned pencil and paper, a spreadsheet, a logbook or a smartphone app to track your levels. If you’re not inclined to do this, your meter will capture up to a certain number of glucose values and let you download them to a computer for your viewing pleasure.
It’s important to look at all of your glucose values to get the big picture — not just a single point in time. By doing so, you can spot trends (for example, your fasting blood glucose levels are consistently above target or you tend to go low every afternoon around 4pm). Your numbers are information for both you and your health-care team to learn how your diabetes treatment plan (medication, food intake, physical activity) are working for you. Bring your logs or, at least, your meter to all of your regular provider visits and make sure your provider looks at your numbers.
Remember: If your blood glucose levels aren’t at goal, ask your provider or diabetes educator what you can do to tweak your diabetes treatment plan. Not every blood sugar that you check needs to be at target, but the closer you keep them within your target range, the lower the chance of complications. And the more often you check your blood glucose, the more information you have at your fingertips (literally) to do a course correction, if needed.
A Registered Dietitian and Certified Diabetes Educator at Good Measures, LLC, where she is a CDE manager for a virtual diabetes program. Campbell is the author of Staying Healthy with Diabetes: Nutrition & Meal Planning, a co-author of 16 Myths of a Diabetic Diet, and has written for publications including Diabetes Self-Management, Diabetes Spectrum, Clinical Diabetes, the Diabetes Research & Wellness Foundation’s newsletter, DiabeticConnect.com, and CDiabetes.com
En Español: ¿Qué es Un Nivel Normal de Azúcar en Sangre?