What Is Normal Blood Sugar? Blood Sugar Chart By Test

Why wouldn’t you want more of the fuel that gives you energy?

Blood sugar, or blood glucose, is fuel for your cells. But high blood sugar can cause damage to any organ in your body. If your blood sugar is too low, your body can’t function properly. You’re concerned because you want your or a loved one’s blood sugar to stay in a healthy range.

In this article, you’ll learn what is normal blood sugar, blood sugar tests, hyperglycemia, hypoglycemia, and how to raise or lower blood sugar.

What Is Normal Blood Sugar?

A normal fasting blood sugar for adults is between 70 and 99 mg/dL (1). A normal blood sugar two hours after eating is under 140 mg/dL. Blood sugar (or blood glucose) is measured in milligrams per deciliter (mg/dL).

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Blood Sugar Ranges Chart By Blood Sugar Test

Result A1C Test

2 to 3 month avg.

Fasting Blood Sugar Glucose Tolerance

(2 hours After Eating)

Random Blood Sugar Test
Diabetes 6.5% or higher 126 mg/dL or Higher 200 mg/dL or Higher 200 mg/dL or Higher
Prediabetes 5.7 to 6.4% 100 to 125 mg/dL 140 to 199 mg/dL  N/A
Normal Below 5.7% 99 mg/dL or below 140 mg/dL or below  N/A

Source: American Diabetes Association


What Level of Blood Sugar Is Dangerous? 

According to the University of Michigan, a blood sugar reading of 300 mg/dL or higher can be dangerous (2). They also recommend telling your medical provider if you have two consecutive readings of 300 or higher. But a reading of 180 mg/dL, or above your target range, is too high.


Why Are High Blood Sugar Levels Bad For You?

Blood sugar, or blood glucose, comes from the foods you eat. At normal levels, glucose gives you energy by fueling your cells (3). But high levels of glucose can cause damage to your blood vessels which can harm any part of your body.

Insulin, a hormone produced in your pancreas, opens your cells to receive glucose for energy. When you eat, the increased blood sugar signals your pancreas to release enough insulin to balance the increased sugar levels. Your blood sugar should lower back to normal when you stop eating for a while. if it doesn’t something is wrong.

A high fasting blood sugar usually means:

  • your pancreas doesn’t produce enough insulin. High blood sugar levels weaken the ability of the cells in your pancreas that make insulin. Your pancreas overcompensates and your insulin levels remain high. But your pancreas eventually loses the ability to make enough insulin.
  • You have insulin resistance. Insulin resistance means your cells are less responsive to insulin.

In either case, your blood sugar remains high. 


What Is Hyperglycemia?

Hyperglycemia is a fasting blood sugar over 125 mg/dL and blood sugar over 180 mg/dL two hours after eating (4). It also could mean impaired glucose tolerance, and pre-diabetes, with a fasting blood sugar of 100 mg/dL to 125 mg/dL.

Although your blood sugar is high, your cells are starving because the sugar can’t enter them. 


What Damage Can High Blood Sugar Cause?

The extra blood sugar that can’t enter your cells can cause serious damage to your blood vessels. If left untreated, damaged vessels due to high blood sugar can cause the following (5):

  • Heart disease
  • Increased infections
  • Gum disease and other dental problems
  • Kidney disease or failure
  • Neuropathy: nerve damage that causes pain or tingling in your feet, legs, or hands
  • Poor circulation to your feet
  • Sexual and bladder problems
  • Stroke
  • Vision loss or blindness
  • Weakened immune system 


What Is Low Blood Sugar?

Low blood sugar, or hypoglycemia, means your blood sugar level falls below what is healthy for you (6). Generally, low blood sugar for people with diabetes is 70 mg/dL (3.9 mmol/L) or lower (7). Work with your health care provider to determine what blood sugar level is low for you.


What Causes Low Blood Sugar?

Causes of low blood sugar include (7):

  • Eating disorders or not eating enough food
  • Excessive alcohol  
  • Hormone deficiencies
  • Kidney or pancreas problems
  • Medications
  • Overproduction of insulin


What Are Low Blood Sugar Symptoms?

Symptoms of low blood sugar include (8):

  • An irregular or fast pulse
  • Anxiety
  • Fatigue
  • Hunger
  • Irritability
  • Numbness or tingling of the lips, cheek, or tongue
  • Pale skin
  • Sweating

Worsening Symptoms of Hypoglycemia include:

  • Blurred vision
  • Confusion
  • Inability to eat or drink
  • Loss of consciousness
  • Seizures


How to Raise Your Blood Sugar Fast

If you have symptoms of low blood sugar, test your blood sugar if you can. Because blood sugar comes from food, a small snack is one of the quickest ways to raise your blood sugar. 

The American Diabetes Association recommends the 15-15 rule (9):

  • Consume 15 grams of carbohydrates to raise your blood sugar
  • Wait 15 minutes 
  • Check your blood sugar
  • if your blood sugar is still below 70 mg/dL, eat another serving
  • Repeat these steps until your blood sugar is at least 70 mg/dL

When your blood sugar is back to normal, eat a meal or snack to keep your blood sugar from lowering again.


Foods/Supplements That Raise Blood Sugar

  • Glucose tablets
  • 4 ounces of juice or non-diet soda
  • A piece of fruit
  • 15 grapes
  • A tablespoon of honey

Glucose is the best treatment for hypoglycemia, but any carbohydrate that has glucose will raise blood sugar (10). But any fat in the food you eat will blunt the glucose spike and keep your blood sugar lower longer. And in type 2 diabetes, protein may increase your insulin response without increasing blood sugar.

 So you shouldn’t use carbohydrate sources high in fat or protein to raise blood sugar.


Reasons For Getting Blood Sugar Tested

Reasons for the A1c test and other blood sugar tests include the following (11):

  • More frequent urination
  • Extreme thirst
  • Chronic infections
  • Extreme tiredness or exhaustion
  • Slow healing of bruises and cuts
  • Feeling very hungry despite being full
  • Numbness or tingling in your hands or feet
  • Blurry vision
  • Unexplained weight loss


What Is The A1C Test?

The A1C test is an average of your blood sugar over the last 2 to 3 months. This nonfasting test measures the percentage of blood sugar attached to hemoglobin which carries oxygen to your red blood cells. The higher your blood sugar, the higher the percentage of blood sugar attached to the hemoglobin.

The A1C ranges are the following (12):

  • Normal: Under 5.7%
  • Prediabetes: 5.7 to 6.4%
  • Diabetes: 6.5% or higher
Result A1C Test
Normal Below 5.7%
Prediabetes 5.7% to 6.4%
Diabetes 6.5% or higher


Abnormal A1c results by themselves don’t mean you have diabetes. Your medical provider will confirm the results with another blood glucose test.


When Should You Get the A1C Test?

The A1C test can help your medical provider with the following:

  • Early detection. Finding prediabetes early helps you make lifestyle changes to delay or prevent type 2 diabetes.
  • Diagnosing diabetes. If you have symptoms of diabetes, the A1C test helps with diagnosis.
  • Monitoring diabetes. A1c tests help your medical provider track the progress of treatments and disease progression.


Who Should Get An A1C Test?

Your medical provider may also recommend an A1C test if you have risk factors for prediabetes. You may meet have these risk factors if you have the following (13):

  • Over 45 years old
  • A family history of diabetes
  • A history of gestational diabetes
  • You’re overweight or obese
  • A sedentary lifestyle
  • High blood pressure or abnormal cholesterol
  • A history of heart disease or stroke
  • Polycystic ovary syndrome (PCOS)
  • Cushing’s syndrome and acromegaly
  • Sleep problems, such as sleep apnea
  • Certain medicines, such as glucocorticoids, some antipsychotics, and some HIV medications


What Is A Fasting Blood Sugar Test?

A fasting blood sugar test measures your blood sugar after fasting overnight. The ranges for fasting blood sugar are the following (14):

  • Normal: 99 mg/dl (5.6 mmol/L) or below
  • Prediabetes: 100 to 125 mg/dl (5.6 to 6.9 mmol/L)
  • Diabetes: 126 mg/dl or higher (7 mmol/L)
Result Fasting Blood Sugar 
Normal Below 100 mg/dL
Prediabetes 100 mg/dL to 125 mg/dL
Diabetes 126 mg/dL or Above

Source: American Diabetes Association

Generally, your medical provider will need two consecutive fasting blood sugar tests 126 mg/dl or higher to diagnose diabetes. Sometimes people with diabetes have normal fasting blood sugar. If your medical provider suspects you have diabetes, they may recommend the oral glucose tolerance test.


Oral Glucose Tolerance Test

The glucose tolerance test measures your blood sugar before and after you drink a liquid containing glucose. To do the glucose tolerance test, you’ll do the following (1):

  1. Fast overnight (or 8 hours) and have your blood drawn to establish your fasting blood sugar level
  2. Drink a liquid containing glucose and have your blood sugar checked 1 hour, 2 hours, and 3 hours later.

The blood sugar ranges for the glucose test at 2 hours are the following:

  • Normal: 140 mg/dL (7.8 mmol/L) or below
  • Prediabetes: 140 to 199 mg/dL (7.8 mmol/L and 11.0 mmol/L)
  • Diabetes: 200 mg/dL (11.1 mmol/L) or higher
Result  Oral Glucose Tolerance Test 
Normal  Below 140 mg/dL
Prediabetes  140 mg/dL to 199 mg/dL
Diabetes  200 mg/dL or Above

Source: American Diabetes Association


What Is the Random Blood Sugar Test?

A random blood sugar test measures your blood sugar at a random time, regardless of when you last ate. A random blood sugar level of 200 mg/dL (11.1 mmol/L) or higher indicates diabetes. But your medical provider will usually repeat the test on another day for a more reliable diagnosis (15). They’ll also most likely do an oral glucose tolerance test to confirm your diagnosis.


What Is Gestational Diabetes?

Gestational diabetes is a type of diabetes found in pregnant women who didn’t have diabetes prior to being pregnant (16). When your medical provider tests you depends on two factors:

  • Average Gestational Risk. If you have an average risk of developing gestational diabetes, your medical provider will usually test about 24 to 28 weeks into your pregnancy.
  • Greater Gestational Risk. If you have a greater risk of developing diabetes, your medical provider may test you earlier. Risk factors include maternal age, obesity at the start of pregnancy, a history of gestational diabetes, a previous history of macrosomia, or a family history of diabetes (17).


Tests For Gestational Diabetes

Generally, tests for gestational diabetes include the glucose challenge test and the oral glucose tolerance test (18).

Glucose Challenge Test: In this test, your medical provider draws your blood 1 hour after you drink a liquid containing glucose. You don’t need to fast for this test. If your blood sugar is above 140 mg/dL, you may also need an oral glucose tolerance test.

Oral Glucose Tolerance Test. This test measures your blood sugar after fasting for 8 hours. See the section above (Oral Glucose Tolerance Test) to learn more.

Your health care provider may recommend an oral glucose tolerance test with or without a glucose challenge test.


Why Is Diagnosing Gestational Diabetes Important?

A study found that adverse pregnancy outcomes were significantly related to gestational diabetes (19). Because of these dangers for mothers and their children, early testing and treatment of gestational diabetes are important.


What Factors Affect Blood Sugar Throughout the Day?

Things that affect blood sugar during the day include (20):

  • Type of food you eat, when you eat, how much you eat
  • Alcohol consumption
  • Dehydration
  • Illness
  • Certain medical conditions
  • Medications
  • Menstrual periods
  • Pregnancy
  • Physical activity
  • Smoking
  • Stress


How To Lower Blood Sugar With Lifestyle Changes

  1. Eat earlier. Because of circadian rhymes in glucose tolerance, eating low-glycemic food at night can cause a higher blood sugar spike than eating high-glycemic foods in the morning (21).
  2. Eat at the same time. Eating at irregular times can raise blood sugar and decrease insulin sensitivity. For example, in one study subjects were randomized to eat their regular diets through six regular meals a day, or three to nine meals at irregular times. Researchers found that eating irregular meals every day can decrease insulin sensitivity (22)
  3. Prevent post-meal blood sugar spikes. Whole-plant foods such as vegetables, fruits, whole grains, beans, and nuts can blunt blood sugar spikes after meals (23).
  4. Try apple cider vinegar. Apple cider vinegar’s possible blood sugar benefit is helping increase glucose uptake into your cells (24). Apple cider vinegar is one of the rare foods that can decrease both blood sugar and insulin spikes.
  5. Eat unsaturated fats, not saturated fats. Unsaturated fats, such as oleate, are found mostly in avocados, nuts, and olives. Unsaturated fats may improve inulin sensitivity (25). Saturated fats, such as palmitate, are mostly in meat, dairy, and eggs. Saturated fats cause insulin resistance
  6. Eat Turmeric. Curcumin, a powerful phytochemical found in turmeric, can help improve your insulin function. Curcumin reduces (26fat levels in your blood. Excess fat in your blood accumulates in your muscle cells and interferes with insulin signaling.
  7. Eat more fiber. Increasing your fiber intake decreases your sugar intake even eating the same amount of sugar. In seconds, you can drink enough apple juice to get the same amount of sugar in five cups of apple slices. Minus fiber, apple juice is absorbed as soon as it hits your intestines and spikes your blood sugar. But the trapped sugar in the apple slices (fiber) absorbs slowly.
  8. Eat whole foods. Rolled oats have a lower glycemic index than instant oats (27) (oats with thinner flakes). And instant oats have a lower glycemic index than powdered oats (28). Why? The physical form of food determines carbohydrate absorption.
  9. Eat a plant-based diet. Eating a vegetarian diet is associated with improved blood sugar (29). There’s a general consensus that whole food plant-based diets help prevent and treat diabetes (30).
  10. Eat more whole fruit. Researchers randomized children and teens to a nutritional intervention to increase the whole plant density of their diet (31). They found that the more whole plant foods such as whole grains, fruit, vegetables, and legumes they ate, the better their blood sugar control.
  11. Stay hydrated
  12. Get quality sleep
  13. Exercise regularly
  14. Monitor your blood sugar. Monitoring your blood sugar helps you determine which foods or stressors spike or lower your blood sugar.


How to Have Normal Blood Sugar and Live A Sweet Life

You’ve worried that your blood sugar may be too high or dip too low. 

Now you know what is normal blood sugar after fasting and after eating. You’ve also learned how to lower your blood sugar naturally with simple lifestyle changes such as eating early in the day. You also learned how to raise your blood sugar quickly if it gets too low.

The good news is that the lifestyle changes that help keep your blood sugar normal also help with blood pressure, weight loss, low energy, and many other health problems. They’ll also give you the energy and freedom to pursue your goals.

What’s your motivation for having a healthy blood sugar level?


Further Reading:

How To Lower Blood Sugar Without Insulin

What Is Normal Blood Pressure By Age?

Resting Heart Rate Chart By Age


Sources Cited

  1. https://www.mayoclinic.org/diseases-conditions/diabetes/diagnosis-treatment/drc-20371451
  2. http://www.med.umich.edu/1libr/MEND/Diabetes-Hyperglycemia.pdf
  3. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes
  4. https://www.ncbi.nlm.nih.gov/books/NBK430900/
  5. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems
  6. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/low-blood-glucose-hypoglycemia
  7. https://diabetesjournals.org/care/article/44/Supplement_1/S73/30909/6-Glycemic-Targets-Standards-of-Medical-Care-in
  8. https://www.mayoclinic.org/diseases-conditions/hypoglycemia/symptoms-causes/syc-20373685
  9. https://www.diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/hypoglycemia
  10. https://diabetesjournals.org/care/article/44/Supplement_1/S73/30909/6-Glycemic-Targets-Standards-of-Medical-Care-in
  11. https://medlineplus.gov/lab-tests/blood-glucose-test/
  12. https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
  13. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance
  14. https://www.diabetes.org/a1c/diagnosis
  15. https://www.medicalnewstoday.com/articles/323022#what-do-the-results-mean
  16. https://www.cdc.gov/pregnancy/diabetes-gestational.html
  17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8548751/
  18. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/gestational/tests-diagnosis
  19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8548751/
  20. https://professional.diabetes.org/sites/professional.diabetes.org/files/media/ada-factsheet-factorsaffectingbloodsugar.pdf
  21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418873/
  22. https://www.nature.com/articles/1601935
  23. https://academic.oup.com/jcem/article/91/3/813/2843304
  24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438142/
  25. https://pubmed.ncbi.nlm.nih.gov/17346204/
  26. https://www.ncbi.nlm.nih.gov/pubmed/22930403
  27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2584181/
  28. https://journals.physiology.org/doi/full/10.1152/ajpgi.00005.2017?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org
  29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4221319/
  30. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5466941/
  31. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919526/

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