Blood Sugar Chart: What's the Normal Range for Blood Sugar?

Last updated: October 20th, 2023

If you have been told to watch your blood sugar levels, you may feel a bit overwhelmed. There is a lot of information to understand, and it's hard to keep track of all of the different numbers and what they mean.

In this article, we will break it all down for you so that it is easy to understand. Let's start by reviewing the basics of how blood sugars work and learning why it's so important to keep your blood sugar levels in check. Then, we will get into what blood sugar levels to aim for, how to monitor your levels at home, and what to do if your numbers are higher than they should be.

Blood sugar basics: what is blood sugar?

The term "blood sugar" refers to the sugar, or glucose, that is floating around in your bloodstream at any given time. Blood sugar, or blood glucose is the main source of sugar found in your blood, and comes from the food you eat.

If you are monitoring your blood sugar, it is important to keep these numbers in check according to the American Diabetes Association (ADA).

Your blood sugar needs to be in the right range for you to be healthy. At least some glucose is necessary for your muscle, liver, and some other cells to use as fuel so they can function.

At least some sugar is necessary for your cells and organs to function properly. When our blood sugar levels get too low, it is called hypoglycemia. Without enough glucose as fuel, we lose the ability to function normally. This can make us feel weak, dizzy, and sweaty. And it can even lead to loss of consciousness.

On the other hand, blood sugar levels that get too high are also harmful, this is called hyperglycemia. Our blood sugar levels can get too high when we don't have enough insulin, or when our insulin isn't working well. This is the case for people who have prediabetes or diabetes. If it isn't treated, high blood sugar can lead to serious problems that can be deadly

The Centers for Disease Control and Prevention (CDC) explains that keeping blood sugar levels in the target range is vital. It can help us prevent serious health concerns like heart disease, vision loss, and kidney disease, for example.

A blood sugar chart can help you remember which levels you should opt for!

Different levels and what they mean

The ranges of safe levels of blood glucose depend on factors such as what time of day it is and when you last ate. Safe levels of blood sugar are high enough to supply your organs with the sugar they need, but low enough to prevent symptoms of hyperglycemia or complications of diabetes which follow the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) guides. Dangerous levels of blood glucose are outside of this range.

The target levels can also vary if you have diabetes. For example, if you are diabetic and are monitoring your blood sugar, you might get a reading of 65 mg/dl. That is considered to be mild hypoglycemia, and you would be wise to eat 15 grams of fast-acting carbohydrates and retest your blood sugar in 15 minutes.

If you were not diabetic, you probably would not know that your sugar was low because you would not test and because you would not symptoms, and you would not act.

That is fine because your body is capable, under normal circumstances, of raising your blood glucose to healthy levels when needed, even if you have not eaten. It is important to keep them in control to help prevent issues like heart disease or nerve damage.

Looking for the best prediabetes diet? Learn what foods are best to help you manage your prediabetes.

What are "normal" blood sugar levels?

You might want to measure your blood sugar before meals to get a baseline, and then two hours after your meal to measure your "normal blood sugar level". Your doctor might also suggest measuring blood sugar before bed to be sure you have been eating well throughout the day and can go to sleep with peace of mind.

These are considered within the range of "normal" for blood sugar:

• Less than 140 mg/dl if you do not have diabetes.
• Less than 180 mg/dl if you have diabetes.

Levels in the Morning

The best time to check blood sugar levels in the morning is right when you wake up and before you eat anything. This gives you a glimpse of what may be happening overnight, and it gives you a baseline for the day.

What should my blood sugar level be when I wake up?

These are goal levels, according to The Joslin Diabetes Center:

• Under 100 mg/dl if you do not have diabetes.
• 70 to 130 mg/dl if you have diabetes.

The dawn effect can often lead to a high morning measurement in diabetes. This is your body's tendency to get ready for the day by raising blood sugar by increasing levels of counter-regulatory hormones – the ones that counteract insulin as in normal blood sugar. For people with diabetes, you do not have the capacity to counterbalance this rise in blood sugar, so levels can be dangerously high.

Ways to lower your morning blood sugar value include:

• Eating dinner earlier
• Checking your medications – making sure you are taking them properly and asking your doctor if they are correct
• Going for a walk after dinner
• Including protein with your dinner

Blood Sugar Levels 2 Hours After You've Eaten

Many foods have types of carbohydrates called starches and sugars. When you eat foods with these types of carbohydrates, your body breaks them down into glucose, which is a type of simple sugar, and releases the glucose into your bloodstream. Aside from glucose produced by your liver, food is the main source of plasma glucose.

Two hours after eating, your blood sugar levels rise. They rise more when you eat more carbohydrates, when you do not eat fiber, fat, or protein with your carbs, and when you eat certain types of carbohydrates, such as refined sugars and starches.

These are target values from The Joslin Diabetes Center, which include levels for people with diabetes:

Blood Sugar Levels During Pregnancy

The NIDDK states that gestational diabetes is high blood sugar that occurs during pregnancy if you were not diabetic before getting pregnant. Healthy blood sugar during pregnancy can help lower your risk of developing type 2 diabetes later. It can also lower the risk of your baby being born prematurely, at a high birth weight, and having respiratory problems.

Blood sugar and insulin levels during the first trimester of pregnancy tend to be lower than usual, but they rise during the late second and early third trimesters. You can be diagnosed with an oral glucose tolerance test (OGTT). [7]

These are the steps for the 2-step strategy.

• Drink a solution with 50 grams (200 calories) of glucose – about the amount in 1 16-oz. bottle of a soft drink
• Get your blood drawn after 1 hour. Ig the value is high, retest‚Ķ
• Fast overnight
• Drink a solution with 100 grams (400 calories) of glucose – about the amount in 12 peanut butter cups
• Get your blood drawn immediately and after 1, 2, and 3 hours

Or, your doctor might use the 1-step strategy with a 2-hour OGTT:

• Fast overnight
• Drink a solution with 75 grams of glucose (300 calories – about the amount in 2 cans of soda)
• Get your blood drawn immediately and after 1 and 2 hours

These are some values to know from NIDKK related to gestational diabetes and healthy blood sugar in pregnancy.

Hemoglobin Chart

Hemoglobin is the oxygen-carrying protein in your red blood cells, but it is highly relevant to blood sugar levels. Sugar in your blood attaches to hemoglobin, creating what is called glycated hemoglobin, or A1c (or Hba1c). High blood glucose levels lead to more hemoglobin being glycated.

Measuring your A1C is an alternative to measuring fasting blood glucose. Measuring blood glucose directly with a finger prick (glucometer) or a blood draw at your doctor's office lets you know your blood sugar at that moment, while the A1c value you get provides an estimate of your average blood sugar levels over the past 3 months.

For example, if your A1c value is 7.8 (a reading between 140-199 mg/dl) would be considered high.

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Printable Blood Sugar Chart

A blood sugar chart showing goal values can help you quickly gauge how you are doing with your monitoring. This chart shows what to aim for throughout the day if you have diabetes or not. [9]

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You can also click here for a printable blood sugar chart showing target values at different times of the day for diabetics and non-diabetics.

Blood Sugar Level Chart by Age

Blood sugar levels tend to rise with age due to an increase in insulin resistance and decrease in insulin sensitivity. In one study by the National Health Institute (NIH), each extra decade of age was linked to a 2.7 mg/dl increase in fasting glucose, and a 4.5 mg/dl increase in 2-hour post-prandial (post-meal) glucose levels.

How to Reduce Blood Sugar

You can take steps to reach your blood sugar goals as soon as you find out that it is high. This is how to reduce blood sugar if you have a single high reading that may be dangerous:

• Ask your doctor what to do if you missed a dose of insulin or another diabetes medication
• Ask your doctor if your medication types and doses are still appropriate for you
• Drink water to dilute the sugar
• Exercise (if safe) for 15 minutes
• Eat a small protein snack, such as a hard-boiled egg, 1/2 ounce of peanuts or pistachios or other nuts, 1/2 cup of beans, or 1/2 cup of plain yogurt or cottage cheese

If you have chronically high blood sugar in prediabetes or diabetes, you can follow this treatment plan:

• Exercise regularly, assuming your doctor approves it
• Lose weight if you are overweight or obese
• Eat a higher proportion of vegetables, whole grains, lean proteins, healthy fats, and fruit
• Limit sugary foods and beverages, fried foods, refined starches, and processed and fatty red meats
• Beware of starchy vegetables such as sweet potatoes, which can spike your blood sugar. Check out our guide of which veggies to avoid!

Glycemic Index Calculator

If you have been tested, then what? A blood sugar level calculator can help you put the results into terms you can understand after you have used a glucose meter. For example, it can convert mg/dl into mmol, or mmol into mg/dl, depending on which value your test results state for glucose levels.

A calculator can also change A1C into EAG, or estimated average glucose.

Calculate yours with the American Diabetes Association's calculator!

Fasting Blood Glucose Level Test Preparation

What should you do if your doctor orders a fasting blood sugar test? The preparation is the same as when you take a fasting test for cholesterol. First, be sure to find out if you need to schedule an appointment for your test (some people need to; others have providers that do not require an appointment for blood tests). Ask your doctor what time is best to take it.

Then:

• Schedule your test if necessary
• Ask your doctor if you need to change any of the medications you take on the morning of the test
• If you normally drink coffee or have caffeine, ask your doctor if that is okay. It may not be, since it affects blood sugar levels
• Fast for at least 8 hours before your test. Usually, an overnight fast is most convenient
• You can drink water

How to Check Your Blood Sugar Levels of Urine at Home

A home urine test can show if you are excreting glucose in your urine. That only happens when blood glucose is high, and not if your values are within a healthy range. The urine test uses a test strip and is simple to do, but is not very precise.

Blood Glucose Tests

Blood tests are more common urine tests for measuring blood sugar. They are precise, quick, and not overly painful. A blood-testing machine is also called a glucometer. It is not being overly dramatic to say that a good home glucometer can be life-saving if you have diabetes, since monitoring with a blood sugar chart is one of the top strategies for controlling it.

A good home glucometer:

• Is simple, fast, and accurate
• Is easy to set up and use
• Pairs with a diabetes smartphone app so you can see your values instantly, track them over time, and get coaching and feedback

Lark Diabetes Coach comes with a complete home glucometer kit that is shipped to you and is easy to set up. The Lark app walks you through setup and reminds you when to take your blood sugar.