Treating diabetes is all about goal setting. When you’re diagnosed, your doctor will give you a target blood sugar (glucose) range. That’s your goal range to stay healthy and avoid complications like nerve damage and kidney disease. Meeting your blood sugar goal is generally done with a combination of diet, exercise, and medication, if needed.
The American Diabetes Association (ADA) says your blood sugar target should be tailored to you based on factors like your age, your diabetes type, how long you’ve had diabetes, and your overall health. In general, a “normal” blood sugar level is:
80 to 130 milligrams per deciliter (mg/dL) before a meal
Less than 180 mg/dL one to two hours after a meal
A1C (a measure of long-term blood sugar control) of less than 7%
Testing your blood sugar often and managing any highs and lows will help you keep your level in a healthy range. Let’s take a closer look at blood sugar ranges, what they mean, and why they’re important.
Why Blood Sugar Levels Matter with Diabetes
Your body’s blood sugar level is controlled by insulin, a hormone your pancreas makes that helps your cells use sugar for energy, according to MedlinePlus. As your blood sugar level rises, your pancreas makes more insulin. This helps keep your average blood glucose level in a safe range.
When you have diabetes, your body either can’t make enough insulin or can’t use this hormone well enough to bring down your blood sugar (the latter problem is called insulin resistance). As a result, too much sugar stays in your blood. Over time, your blood sugar gradually rises.
Sustained high blood sugar is a problem because it damages blood vessels all over your body, says the National Kidney Foundation. Those blood vessels carry vital oxygen to your body’s organs and tissues. Damage to them can cause complications like:
Dementia
Erectile dysfunction
Foot damage, such as reduced blood flow, nerve damage, infections, and poor healing of wounds
Nerve damage called neuropathy
Keeping your blood sugar in a healthy range can help prevent these and other complications. That’s why it’s important to know your target range and follow your treatment plan to maximize the amount of time you stay in that range.
How Blood Glucose Is Measured
Your doctor can check your blood sugar in a few ways, according to the Centers for Disease Control and Prevention (CDC). One is with a fasting blood sugar test, which you take in the morning after you’ve fasted all night. Another is with an A1C test, which shows your average blood sugar level over the last two or three months. These are two of the main tests used to diagnose diabetes.
“Testing for diabetes is pretty simple these days,” says Kasia Lipska, M.D., a specialist in diabetes medicine and management at Yale Medicine in New Haven, CT. But, she adds, “no test is perfect, so we usually recommend that if something is abnormal, [the test] be repeated so that it’s confirmed.”
If you’ve been diagnosed with diabetes, your doctor will talk with you about self-monitoring your blood sugar at home. This is essential for people who are taking insulin, which includes all people with type 1 diabetes and some with type 2 diabetes. It’s also recommended for pregnant people with diabetes and some non-insulin-using people with type 2 (for example, if they are having a hard time reaching their blood sugar goals), according to the ADA. There are two main ways of self-testing your blood sugar: A glucometer (glucose meter), in which you test a drop of blood from your finger, or a continuous glucose monitor (CGM), a special device that constantly monitors your blood sugar.
Your doc will give you instructions on when and how often to test and how to interpret the results. The frequency will vary depending on what type of diabetes you have and other factors, according to Cleveland Clinic. Common times you may be advised to check your blood sugar include when you wake up, before and after meals, before and after exercising, and before going to bed at night.
Normal Blood Sugar Ranges
Your blood sugar is considered “normal” if it falls into these ranges, per the ADA’s Standards of Care in Diabetes—2023 (note that your doctor might adjust these numbers based on your age and health):
People Without Diabetes
Fasting: 99 mg/dL or less
After Eating: 140 mg/dL or less
A1C: Less than 5.7%
Most Adults With Type 1 or Type 2 Diabetes
Fasting: 80-130 mg/dL
After Eating: Less than 180 mg/dL
A1C: Less than 7%
Children With Type 1 or Type 2 Diabetes
Fasting: Personalized to the child
After eating: Personalized to the child
A1C: Less than 7% in many cases but depends on the child
People With Gestational Diabetes (Diabetes During Pregnancy)
Fasting: 60-90 mg/dL
After Eating: Less than 140 mg/dL one hour after a meal or less than 120 mg/dL two hours after a meal
A1C: Less than 6%
People With Prediabetes
Fasting: 100-125 mg/dL
After Eatng: 140-199 mg/dL
A1C: 5.7% to 6.4%
Let’s look at each of these groups in more detail.
Normal Blood Sugar for People Without Diabetes
An A1C test result below 5.7% or a fasting blood sugar of 99 mg/dL or lower means that you don’t have diabetes, says the CDC. If your A1C level is between 5.7% and 6.4% or your fasting blood sugar is between 100 and 125 mg/dL, you may have prediabetes. This means your blood sugar is higher than normal, but not high enough for your doctor to diagnose you with diabetes. As many as one in three adults in the U.S. (about 96 million people) has prediabetes, according to the CDC, and around 80% of them don’t know they have it. Prediabetes often shows no symptoms for years.
If your blood sugar is higher than normal, your doctor might order follow-up testing. One test you might have is an oral glucose tolerance test. This test checks your blood sugar before and after you drink a sugary liquid. A normal result is 140 mg/dL two hours after the test. A result of 140 mg/dL to 199 mg/dL is considered prediabetes, says the CDC.
If your results are in the prediabetes range, your doctor might order more tests and offer ideas for lifestyle changes to help bring down your blood sugar levels. The goal is to lower your risk of developing type 2 diabetes or delay it for as long as possible.
Normal Blood Sugar for Adults with Type 1 and 2 Diabetes
The ranges above (blood sugar 80-130 mg/dL fasting, less than 180 mg/dL after eating, A1C below 7%) apply to most adults with either type 1 or type 2 diabetes, according to the ADA. However, expect some personalization of these numbers based on your specific health needs.
Blood sugar that’s above the recommended range is called hyperglycemia (high blood sugar). Blood sugar lower than the range is called hypoglycemia (low blood sugar). Careful monitoring of your blood sugar is important regardless of the type of diabetes you have, but it’s especially important if you are taking insulin. Talk with your doctor about which self-monitoring method—glucometer (glucose meter) or wearing a CGM—makes the most sense for you.
Staying in the healthy range for as long as possible during the day, called your “time in range,” can help prevent diabetes complications. Aim for a time in range of about 70% of readings, which equals around 17 hours per day, says the ADA.
Normal Blood Sugar for Children with Type 1 and Type 2 Diabetes
Managing blood sugar in kids with diabetes is definitely not one-size-fits-all. Your doctor will come up with a target based on your child’s medication and other considerations.
The ADA recommends an A1C level of less than 7% for many children with type 1 and type 2 diabetes. But the target for some kids might be higher (7.5 or 8%) or lower (6.5%) depending on their medication and other factors.
Like adults with type 1 diabetes, children with type 1 must check their blood sugar several times a day with a glucometer or wear a CGM to monitor their glucose fluctuations through the day, according to the ADA. If your child has been diagnosed with type 2 diabetes, their doctor will advise you on how often to test their blood sugar.
Normal Blood Sugar for Pregnant People with Diabetes
Whether you came into pregnancy with diabetes or developed it during your pregnancy—called gestational diabetes—high blood sugar shouldn’t stop you from having a healthy baby. You will have to monitor and manage your blood sugar more carefully during pregnancy, though, to avoid complications like preeclampsia (dangerously high blood pressure in pregnancy), birth defects, and miscarriage, says the ADA. Having uncontrolled diabetes also increases your baby’s risk for obesity, high blood pressure, and type 2 diabetes later in life.
Check your blood sugar before you eat and an hour or two after a meal, says the ADA. Aim for these numbers:
Fasting blood glucose: Less than 95 mg/dL
After eating: Less than 120 mg/dL-140 mg/dL
You’ll notice that these targets are lower than those for nonpregnant people with diabetes. This is because high blood glucose poses such a great risk to the developing baby, according to the ADA. Your A1C target will be slightly lower, too: below 6%, but your doctor may let you go to 7% if you’re at risk for low blood sugar. Using a CGM along with your pre- and post-meal blood sugar checks can help you get to your goal, per the ADA.
Factors That Affect Your Blood Sugar Level
A number of factors can cause your blood sugar to spike (quickly rise). Eating or drinking sugary foods are obvious ones. Other triggers are more surprising; per the CDC, being dehydrated, skipping breakfast, getting too little sleep, and being sunburned can all raise your blood sugar. Blood sugar spikes are especially dangerous if you have diabetes, because your body can’t regulate, or even out, your blood sugar.
Other factors can make your blood sugar fall; for example, extreme heat can cause blood vessels to dilate (widen), the CDC says. That makes insulin absorb more quickly and could lead to low blood sugar. The agency advises checking your blood sugar before and after any new activity or food to see how you respond.
Is A1C the Same as Daily Average Blood Sugar?
A1C and daily average blood sugar are two different measurements, though they both involve averages. The average displayed on your blood glucose meter is the average of the readings that were taken that day—each of which represents only a single point in time, according to the ADA. A1C, is contrast, gives you an average measurement of your blood sugar level over the last two to three months. It captures your blood sugar 24 hours a day over that two- to three-month period.
Since people with diabetes are likely to check their blood glucose more often when they are low (for example, first thing in the morning and before meals), the average of readings on their glucose meter is likely to be lower than their A1C, the ADA says. Complicating matters, how do you compare the two when daily blood sugar is measured in mg/dL and A1C is given as a percentage? Turns out, A1C can be converted into a measurement called eAG (estimated average glucose) that’s reported in the same unit of measurement—mg/dL—as blood glucose meter readings. (The ADA has a calculator that health care professionals can use to do this.) This allows you and your doctor to compare apples to apples when looking at A1C vs. your daily average readings.
What to Do If You Experience Hypoglycemia
Hypoglycemia, where your blood glucose drops lower than 70 mg/dL, is common in type 1 diabetes. Your blood sugar can drop if you take too much insulin, wait too long before eating or don’t eat enough carbs, or exercise more than usual, says the CDC. Hypoglycemia can also happen in type 2 diabetes if you are taking insulin or another medication to lower your blood sugar.
If you have hypoglycemia, the solution might be as simple as eating something that raises blood sugar, such as 4 ounces of fruit juice or 3-4 glucose tablets. If you are ever unresponsive or too confused or lethargic to consume glucose, your doctor might prescribe an injectable medication called glucagon. It is extremely important to have this medication on hand if you take insulin.
The 15-15 Rule
The 15-15 rule is a helpful method the ADA recommends to raise your blood sugar when it’s below 70 mg/dL. Eat 15 grams of carbohydrates, then wait 15 minutes and check your blood sugar level again. Sources that provide about 15 grams of carbs include:
Glucose tablets (see instructions)
Gel tube (see instructions)
4 ounces (1/2 cup) of juice or regular soda (not diet)
1 tablespoon of sugar, honey, or corn syrup
Hard candies, jellybeans, or gumdrops—see food label for how many to consume
If your blood sugar is still too low, repeat the process until you’re back in your target range. Afterward, try to eat something nutritious and low in fat (fat slows the absorption of sugar) to make sure your blood sugar doesn’t dip too low again.
Takeaways
Blood sugar is an important measurement to help manage diabetes and prevent long-term complications of this condition. Work with your doctor to figure out a healthy range for you. From there, a doctor and other diabetes specialists can coach you on lifestyle changes to help you keep your numbers in range.
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