What’s Normal Blood Sugar?


Steven P Parker MD

Steven P Parker MD

Thank you for dropping in! If you need help lowering your blood sugar level, check out my books at Amazon or Smashwords. If you’re outside of the U.S., Smashwords may be the best source.

—Steve Parker, M.D

*    *   *

Physicians focus so much on disease that we sometimes lose sight of what’s healthy and normal.  For instance, the American Diabetes Association defines “tight” control of diabetes to include sugar levels as high as 179 mg/dl (9.9 mmol/l) when measured two hours after a meal.  In contrast, young adults without diabetes two hours after a meal are usually in the range of 90 to 110 mg/dl (5.0–6.1 mmol/l).

What Is a Normal Blood Sugar Level?

The following numbers refer to average blood sugar (glucose) levels in venous plasma, as measured in a lab.  Portable home glucose meters measure sugar in capillary whole blood.  Many, but not all, meters in 2011 are calibrated to compare directly to venous plasma levels.

Fasting blood sugar after a night of sleep and before breakfast: 85 mg/dl (4.7 mmol/l)

One hour after a meal: 110 mg/dl (6.1 mmol/l)

Two hours after a meal: 95 mg/dl (5.3 mmol/l)

Five hours after a meal: 85 mg/dl (4.7 mmol/l)

(The aforementioned meal derives 50–55% of its energy from carbohydrate)

♦   ♦   ♦

Ranges of blood sugar for young healthy non-diabetic adults:

Fasting blood sugar: 70–90 mg/dl (3.9–5.0 mmol/l)

One hour after a typical meal: 90–125 mg/dl (5.00–6.9 mmol/l)

Two hours after a typical meal: 90–110 mg/dl (5.00–6.1 mmol/l)

Five hours after a typical meal: 70–90 mg/dl (3.9–5.00 mmol/l)

Blood sugars tend to be a bit lower in pregnant women.

♦   ♦   ♦

What Level of Blood Sugar Defines Diabetes and Prediabetes?  

According to the 2007 guidelines issued by the American Association of Clinical Endocrinologists:

Prediabetes: (or impaired fasting glucose): fasting blood sugar 100–125 mg/dl (5.6–6.9 mmol/l)

Prediabetes: (or impaired glucose tolerance): blood sugar 140–199 mg/dl (7.8–11.0 mmol/l) two hours after ingesting 75 grams of glucose

Diabetes: fasting blood sugar 126 mg/dl (7 mmol/l) or greater

Diabetes: blood sugar 200 mg/dl (11.1 mmol/l) or greater two hours after ingesting 75 grams of glucose

Diabetes: random (“casual”) blood sugar 200 mg/dl (11.1 mmol/l) or greater, plus symptoms of diabetes

If there’s any doubt about the diagnosis, testing should be repeated on a subsequent day.

Compared to impaired fasting glucose, impaired glucose tolerance may be a better predictor of cardiovascular disease and death.  So some researchers and clinicians focus on preventing high blood sugar swings after meals.  The problem with prediabetes, which causes no symptoms early on, is that one of every four cases progresses to full-blown diabetes over the next 3–5 years.

The numbers above do not apply to pregnant women.  Five percent of pregant women develop gestational diabetes that goes away soon after delivery.

♦   ♦   ♦

Looks like a great place to hike

Looks like a great place to hike

What Level of Hemoglobin A1c Defines Diabetes?

Another way to consider normal and abnormal blood sugar levels is to look at a blood test called hemoglobin A1c, which is an indicator of average blood sugar readings over the prior three months.  The average healthy non-diabetic adult hemoglobin A1c is 5% and translates into an average blood sugar of 100 mg/dl (5.6 mmol/l).  This will vary a bit from lab to lab.  Most healthy non-diabetics would be under 5.7%.

In December, 2009, the American Diabetes Association established a hemoglobin A1c criterion for the diagnosis of diabetes: 6.5% or higher.  Diagnosis of prediabetes involves hemoglobin A1c in the range of 5.7 to 6.4%.  The aforementioned blood sugar criteria can also be used.

♦   ♦   ♦

What Are Blood Sugar Goals During Treatment For Diabetes?

The 2007 guidelines of the American Association of Clinical Endocrinologists “encourage patients [both type 1 and 2] to achieve glycemic [blood sugar] levels as near normal as possible without inducing hypoglycemia [low blood sugar].”  Specifically:

Fasting blood sugar:  <110 mg/dl (6.1 mmol/l)

Two hours after a meal: <140 mg/dl (7.8 mmol/l)

Hemoglobin A1c: 6.5% or less

The American Diabetes Association recommends normal or near-normal blood sugar levels, and defines “tight control” as:

1) pre-meal and fasting glucose levels of 70–130 mg/dl (3.9–7.2 mmol/l)

2) sugars under 180 mg/dl (10.0 mmol/l) two hours after start of a meal

3) hemoglobin A1c under 7%.

A hemoglobin A1c of 7% is equivalent to average blood sugar levels of 160 mg/dl (8.9 mmol/l).  Hemogobin A1c of 6% equals, roughly, average blood sugar levels of 130 mg/dl (7.2 mmol/l).  But remember, healthy non-diabetics spend most of their day under 100 mg/dl (5.6 mmol/l) and have hemoglobin A1c’s around 5%.

Diabetic experts actively debate how tightly we should control blood sugar levels.  For instance, Dr. Richard K. Bernstein—a type 1 diabetic himself—recommends keeping blood sugar levels under 90 mg/dl (5.0 mmol/l) almost all the time.  If it exceeds 95 mg/dl (5.3 mmol/l) after a meal, then a change in medication or meal is in order, he says.

Here’s the over-simplified “tight control” debate.  On one hand, tight control helps prevent and may reverse some of the devastating consequences of diabetes.  On the other hand, tight control in diabetics on insulin and certain other diabetic medications may raise the risk of life-threatening hypoglycemia and may shorten lifespan in other ways.

♦   ♦   ♦

Blood Sugar Goals For My Personal Diabetic And Prediabetic Patients

Ideally, normal glucose levels before and after meals, with normal hemoglobin A1c.

Realistically, these are acceptable fall-back positions:

Fasting blood sugar: under 100 mg/dl (5.6 mmol/l)

One hour after meals: under 150 mg/dl (8.3 mmol/l)

Two hours after meals: under 130 mg/dl (7.2 mmol/l)

Hemoglobin A1c: 6% or less

Treatment options for those not at goal include diet modification, weight loss, exercise, and medications.  Admittedly, those goals are not acceptable or achievable by everyone with diabetes.  Future studies may prove that such strict goals are not necessary to avoid the complications and premature death suffered by people with diabetes.  Tight control may be less important for elderly diabetics over 65–70 years of age.  But for now, if I were a young or middle-aged diabetic I’d shoot for the goals above.

Steve Parker, M.D.

Technical Notes

The gold standard for measuring glucose is a large chemistry analyzer in a lab, which measures values in plasma obtained from a vein with a needle.  The glucose level in capillary whole blood, obtained via fingerprick  and analyzed on a portable/home glucose monitor, is a different value, often 5–10 mg/dl (0.3–0.6 mmol/l) higher than venous glucose.  As of 2011, a majority of home glucose monitors, but not all, are calibrated so as to be directly comparable to venous plasma glucose readings.  Read your monitor’s paperwork to find out about your device.

Portable fingerstick glucose meters are not as accurate and as you might expect.  If your actual glucose level is 100 mg/dl (5.6 mmol/l), the meter may report it as 80 or 120 mg/dl (4.4 or 6.7 mmol/l) or anywhere in between, for example.  The meters tend to be less accurate at glucose values over 200 mg/dl (11.1 mmol/l).  Some devices are definitely more accurate than others.  Research the available devices before you acquire one.

Outside the U.S., glucose is usually reported in units of mmol/l (millimoles per liter).  One mmol/l = 18 mg/dl.  To convert mg/dl to mmol/l, divide by 18 or multiply by 0.055.

Last modification date: September 16, 2011

42 responses to “What’s Normal Blood Sugar?

  1. i have problem with all lab reason no 1-what is the normal range of blood sugar in mmol/l or mg/dl ? every DR tells you different story about normal range for blood sugar. i am a diabete person when i did blood test for hba1c the result it comes 7.2 it tells sametime it is good and sometime it tells me bad. from this point what can learn is how can i trust DR and the lab.

  2. Hello, Neat post. There is an issue together with your website in internet explorer,
    may check this? IE nonetheless is the marketplace
    leader and a big component to folks will pass over your fantastic writing due to this

  3. Thank you for this information. This really helped put into perspective what numbers I should aim for, since I am not able to keep under 100 all the time, even though I’ve eaten a low carb diet for the last 2 years.

  4. My blood glucose fasting is 4,4, I tested after several meals (green smoothies, sweet potatoes with vegetables and coconut milk, rice crackers with peanut butter) and my blood sugar never was higher than 5.9 post meal. And after 2 hours it is already back at about 4.6 … But I guess thats good 😛

    • Oh and btw I eat high carb, I think high carb gives me a really good blood glucose responds. Also it are good carbs not bad ones like junk and candy. I also eat enough fat, but most of my calories come from carbs.

  5. ADA defines tight control as under 7%? Even my “whole grains are great” GP would not be satisfied with that. Pathetically out of step. How can they be taken seriously? And how common are complications with an A1C that high Dr. Parker year after year versus one in the mid 5s or lower? I can guess the answer to that one…no need to respond. Donate to the ADA for garbage like that? Don’t think so…

  6. Thanks for your response Dr. Parker and for all your efforts with your blogs…they are extremely informative and helpful. I did ask my GP about insulin to drive my A1C even lower than its current 5.6. She said that would be very dangerous since I have good control and the danger of hypos is very real.

  7. I’ve used the finger prick glucose devices a lot – I had no idea they could be so inaccurate! Thanks for the handy guide to blood glucose numbers – I definitely remember trying to look them up before – good to have them all in one place.

  8. its been suggested that 20-30 mins walk makes wonder in reducing blood sugar levels. but jz curious to know how long it takes to have change in the readingsi mean how many days/weeks/months after we can see a change on it? pls reply

  9. Adeyanju mariam

    I did my blood sugar level test two days ago… And i tink I Did it like an hour after eating beans that night… And my result was 7.2mmol/L… Is my result normal or abnormal? … If it is abnormal what should i take to make it normal

    • I don’t know your health status but if you are non diabetic adult then i can say its abnormal as compared to the ranges Doctor has given and my knowledge about diabetes.You can increase your water intake.That will help you to reduce the sugar through urine.

      • Gina, I wouldn’t depend on increased water intake to lower blood sugar levels.
        On a related note, I do see many emergency department physicians prescribe intravenous water (actually normal or half-normal saline) to acutely lower blood sugars that are over 400 mg/dl (22 mmol/l). It often seems to work, at least for the short term. I wonder if it’s just a dilutional effect related to increasing blood volume. For example, if you add a half tsp of table sugar to 4 oz of water in a glass, you have a certain concentration of sugar. Add another once of water, and you immediately have a lower sugar concentration.

  10. I have very blurred vision in the morning also most of the day ,
    my fasting blood sugar is 5.3 1st thing , I have a dry mouth and slightly dizzy

  11. I took my blood sugar level before breakfast, the reading was 5.3 . My doctor said that I was pre diabetic. Is she right ?

  12. During the day after eating my blood sugars go up to 12 and 13. But come down slowly. In the morning my reading is around 5. Should I be on tablets?

    • For my American readers, note that 12-13 mmol/l of glucose is about 225 mg/dl, and 5 mmol/l is 90 mg/dal.
      Nerida, if it were me, I’d want to do something to keep my glucoses under 160 mg/dl (9 mmol/l) or so most of the time. Options include medications, diet, exercise, bariatric surgery, loss of excess weight, others.

  13. Katie Freeman

    Hello, I am a 48 y.o. female, 5’6.5″ who weighs 202 lbs. My A1c level is 5.4% and my recent non fasting c-peptide level was 4.0 (1.1-4.4) and my insulin total was 10.4(2.6-24.9). My glucose level was 79, also non fasting. I am not a diabetic, but I saw my endocrinologist who is monitoring a non cancerous thyroid nodule, and she was not very happy that I scheduled an appointment with her. Is it normal for my glucose level via a glucometer to be 134 dL/ml 15 minutes after a cup of coffee with Splenda and about 12 g of creamer carbohydrates and then to drop to 75 dL/ml 30 minutes later? I got hot, shaky, and confused. My glucose levels have dropped into the upper 50s and low 60s within 30 mins of meals, or even hours later, with the same Sx. I’m so tired that I’m falling asleep while driving too. I know I’m getting plenty is sleep, but my 25 D hydrox was 22.8. I feel like I’m being ignored, but I know I feel bad and something has changed within the last 2 months. Thank you

    • Granulated sugar alternatives have a higher glycemic load than sugar because of the bulking agent maltodextrin. You may have had reactive hypoglycemia from it by the readings and symptoms. Might be a one off caused hormonally or something you should monitor through diet.

  14. Hello, my normal blood sugar has always been 5.4 For the past 4 months I have been following a LCHF way of eating and have lately been fasting 1/23
    Meaning I eat one meal a day at lunch. High fat very low carb. My Blood sugar is ranging from 3.2 – 3.6 Is this okay?
    I am wondering if I am doing some sort of damage and my end up with Diabetes? I have asked this question on several fb pages and websites and no one can give me an answer. I hoping you can. Thank you very much.

  15. I read on the pharmaceutical review that that metformin tablets for diabetes increases your weight, dameges your kidney over time. I am at 6.1 fasting and I am concern about continuing this medication. Can I change my diet and increase exercise to lose weight rather than just consume this pill. I am concerned on the long term damage that metformine does, while I still have a change to go healthy and live normal pre-diabetic.

  16. Maureen malasaga

    Hi! I am 16 years old girl, my weight is 54, and I am pre diabetic before and I just checked my blood sugar yesterday two hours after eating a high carb meal (spaghetti and potato) it said 114 is it normal or not? I have checked it as well before and my fasting blood sugar is 87. I haven’t tried lab test yet cuz my mom won’t let me telling me I’m just being paranoid. I hope you could answer thank you so much 😃

  17. Hi! I’m a 16 year old girl my weight is 54, before I was prediabetic as I was overweight and do eat a lot of sweets. Yesterday I got ny blood sugar checked after a two hour high carb meal (spaghetti and potato) it’s 114mg/dl so I was kinda worried if it’s too high or normal, I have it checked before I think 2 and 1/2 hour of eating biscuit and it’s 87mg/dl, anyway unlike before I don’t really eat sweets that much but I still do and lessen the amount of rice I eat. I haven’t done a lab test yet because my mom just won’t want me to and only tell me I’m paranoid. I hope you can give me an answer. Thank you so much

  18. Hi iam sadia sami my age 47 i check my suger lab aga khan its a famous hospital in pakistan karachi my suger level blood fasting 170 after 2 days i check 139 and random 180 m my cause histrey i have saver astma elargy from TOBAKO cigarette smoke . During this problum my dr sajest you take cortizon heavy doss in this during my one oppration for ovrey remove there is a simmple tumer they can be remove . During oppration they give me cortizon doz . My mother also suger pashint. Please help what can i do for thanks

    • Sadia, it is true that cortisone and other corticosteroid drugs used for asthma (and other conditions) can cause increases in blood sugar above the normal range. The elevated sugars are seen when the drug is in your body, and perhaps a few days thereafter. A short course of steroids does not turn someone into a long-term diabetic.
      I hope this is helpful.

  19. Crystal. DeLanoy

    Hi my name is crystal. Just want want to know if my while blood count to normal. Its reading up 4.9 k/UK lu. Pls. Let me know if they that is ok???? So if u can get back to me to I will,. Thanks hope to hear back soon! Thanks again crystal.

    • Hi, Crystal. I’m used to thinking of white blood cells in terms of microLiters or cubic milliliters, and the normal range is about 4,500 to 10,500. Normal ranges easily vary a bit from lab to lab.
      “k/UK lu” is not the units provided by the labs I use in the U.S.A., so I don’t know the normal WBC count in those units.

    • Hi Crystal, yes that reading is ok, it’s normal I would say and I don’t think you have anything to worry about.

  20. My HDL is 20, triglycerides are 1,330, and HDL was 20, fasting sugar is 85, and my A1C was 4.7 (Low) I thought high triglycerides was caused by high blood sugars? I do have mild fatty liver disease, and my fasting insulin level was 14.30mlU/Ml, not over weight either, strange

  21. Thanks for a very comprehensive and informative post. I mostly love the fact that you offer a conversion for the readings – mg/dl to mmol/l.


    I have been diagnosed 6 months ago with been diabetic, my doctor prescribed METFORMIN 500MG, for me to take and told me if I feel sick or feel I am having what might seem as side effect’ then I must come back to her and she will try another medication. Of course I refused to take the medication, being a NURSE I have seen the many side if side effects of medication. Diabetes type 2 is reversible so I decided to take my will power back into my hands by dieting and eating all what is suppose to be a healthy choice. I cut out most carbohydrate from my diet, but still eat sweet potatoes, pulses, lentils, beans lots of green vegetables, chicken and mainly steam fish. I decided I do not want to rely on medication for my diabetes. My fasting blood sugar level was 8.7 [157 mg/dl] and now my fasting blood sugar level is between 5.4mmol/L – 5.7mmol/L [97 and 103 mg/dl]. When I am hoping it goes down to the normal level. Please could you tell me if a reading between 5.4mmol/L _5.7mmol/L is high.

    • Cecille, congratulations on your lower fasting sugar levels. I’ve converted your mmol/L readings into mg/dl and added them to your comment above.
      For young healthy non-diabetics, normal fasting glucose levels are 70–90 mg/dl or 3.89–5.00 mmol/L.

  23. All this chat and no mention of Intermittent fasting. Former U-500 Insulin and Metformin user now no diabetes medication for over 1 year last A1c 6.4… 16/8 intermittent fasting and thanks to Dr. Jason Fung’s findings and info on the matter. More Doctors need to be educated about it instead of passing out pills and needles !!!!

  24. Hi my name is basim I just would like to ask you help to answer my question please.l have a concern that my blood sugar is abnormal .my blood sugar while I’m fasting is 5.6 and after meal is 7.6 is that normal? Cheers

  25. Can blood sugar be cured or reversed or stabilized in such a way that you stop taking treatment?

Leave a Reply to Nerida Cancel reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s