Before we dig into this discussion, let’s just do a recap on fasting blood sugar levels – the numbers.
The goal ranges do vary slightly depending on the recommending agency, but generally you’ll see these ranges:
- Between 70-100 mg/dL or 4-5.6 mmol/l (optimal)
- 70-110 mg/dL or 4-6 mmol/l (still good control)
- 70-130 mg/dL or 4-7.2 mmol/l (more liberal, but realistic for many)
So now that we’ve got those numbers straight, let’s review some reader questions regarding fasting blood glucose levels.
If you have your own questions after reading this, just leave your comments below.
Why are my numbers low at night and high in morning?
There are several reasons why your blood sugar may be higher in the morning.
First, remember that diabetes is a progressive disease in which the hormones produced by the body can become insufficient and lack the ability to compensate for glucose in the bloodstream. On top of this, insulin resistance prevents cells from accepting glucose efficiently.
Now, keep in mind that while your body is physically resting overnight, your mind does not take any breaks – the brain is still very active and so are your organs.
During the night, your hormones are very busy at work restoring and repairing your body from the day and preparing it to wake up. In order to do this, there is a release of a group of hormones around 3-4 am, which provides the energy needed to wake you up — one of the effects of this is glucose in the bloodstream. This is called “Dawn Phenomenon” and drives up sugar levels.
Another possibility is something called “Somogyi Effect.” This is when glucose levels drop super low overnight, which activates your emergency backup system, again triggering hormones and sending messages to the liver and muscles to send sugar into the system, which as a result can bounce them back real high. The Somogyi Effect occurs more often in those taking insulin.
You can read more about the Dawn Phenomenon and Somogyi Effect here.
Furthermore, if you are sleeping poorly or even having intense dreams, this can affect hormones as well.
Finally, sometimes medications that are taken earlier in the day (which were helping you maintain good control) may wear off toward the morning.
When is the best time to take a fasting measure of blood sugar?
It’s best to test your blood sugar right when you get up.
If you make it part of your morning routine, such as after you go to the bathroom or brush your teeth, it’s easier to remember.
Keeping your supplies by your nightstand or in the bathroom or kitchen–wherever you are apt to remember–will help facilitate this.
What is the most reliable way to take a blood sample? Is the side of the finger as good as the palm or elsewhere?
The fingertips are the best place to test and get the most accurate readings.
The reason for this is that they are the best site for the end capillaries.
You can lance anywhere on the fingertip, but I always advise using the sides for 2 reasons:
1. Less nerve endings=less pain!
2. You have 2 sides to every finger (plus your thumbs) so you’re doubling the rotation options leaving your fingers less sore and less likely to build up callouses from poking.
How does fiber affect glucose levels and carb intake? Should I increase fiber intake possibly at night and would it help lower my numbers in the morning?
There are several different types of fibers–and only a few (if any) really help directly with glucose levels.
There are certain fibers that help with cholesterol, certain ones that help with bowel movements and ones that aid in blood sugar regulation. While all fiber is healthy to eat they are not all the same.
Viscous soluble fiber seems to be the only fiber that helps with blood sugar control.
Sources of soluble fiber include psyllium husks and chia seeds, along with artichoke, asparagus, winter squash, Brussels sprouts, broccoli, onion, carrots, blueberries and nuts.
It’s hard to say whether increasing fiber in the evening would help your morning levels because it depends on a lot of factors (what else you’re eating, the type of fiber etc). But it is likely that if you substitute higher fiber foods for lower fiber ones, that is a smart move.
Try to make sure your fiber is coming from non starchy vegetable sources rather than grains/starchy stuff (which will also raise your blood sugar).
What can I eat at night to lower levels in the morning?
There has been one small study that has shown eating 1 ounce (28g) of cheese (which is just 1 slice cheese), along with consuming 2 tablespoons of apple cider vinegar (mixed with water) before bed, may help lower blood sugar levels by 4-6%.
Other than that, there is nothing specific you can eat that will lower your blood sugar levels.
However, you can replace higher carb meals for lower carb meals. You can exercise regularly. You can manage your stress and take measures to ensure you are sleeping soundly.
All of these can help reduce the glucose load on the pancreas and make cells more sensitive to insulin, which will have the effect of lower morning levels also. The tighter control you gain on an everyday basis, the better.
I swim 2 kilometres (1.2 miles) every morning, 6 days a week. I have taken blood sugar readings on waking and it’s around 6.2 (111). When I return from swimming the reading is 6.8 (122). Why? Most waking hours my blood sugar is between 4.0-6.0 (72-108). I only have higher readings in the morning. Any official fasting blood tests have been performed in the morning after swimming. Should I take my next fasting blood test a couple of hours later? Would appreciate any suggestions on reducing my waking blood sugar.
Kudos on the exercise!
My first question is whether you eat breakfast before your morning workouts? If the answer is no, this would not be a good route to take.
It is important for your body to have sufficient fuel, especially with your routine. Inadequate energy for fuel sends stress signals to the body which tends to raise glucose.
The next question is the intensity of your workouts–if they are very intense, adrenaline gets released and this will elevate glucose.
An interesting experiment would be to test before and after a light, moderate and intense workout to see if the intensity is what’s causing a rise in levels.
Another experiment would be to play around with your breakfast beforehand, first ensuring you are eating breakfast, then perhaps altering what you eat to include more or less healthy carbs and protein.
My blood sugar is always high in the morning. Any help?
See above for some of the various causes for high fasting levels.
It is difficult to know what is causing them as there are so many factors to consider – diet, sleep, stress, exercise, along with your body’s own individual metabolic state.
If you’re really struggling, I would encourage you to meet with a Diabetes Educator or physician you trust to discuss your particular situation. They may suggested alterations of your medications or timing.
But just to recap – maintaining a healthy weight, regular physical activity and a balanced low carb diet are some of the best lifestyle habits to embrace to get these levels under control and prevent/ delay diabetes progression.
What do I do if fasting numbers are higher than the night before?
Again I would suggest discussing your particular situation with a trusted professional. It depends on how much higher they are than the previous night…and how high they were at night.
For example, if they are 250 (13.8) in the morning, but 170 (9.4) the night before — then both of those numbers need to be addressed, as they are both higher than normal.
On the other hand, if they are in range the night before but elevated in the morning, there are various options to explore, most of which have already been mentioned above.
But again, it will always depend on many factors — if you wake up with 140s (7.8s), that is much different than waking up with 350s (19s).
The best advice is to focus on the proper lifestyle changes (see above and throughout our blog!) and seek medical help for the rest.
Please pin, tweet or share this discussion and get others involved in the conversations. Thanks. 🙂
And if you have questions of your own, leave them below and I’d be happy to answer them.
Lori
My avg fasting (over 30 days) is 6.5 mmo/L
before meal is 6.1
After meal is 6.8
I have seen only a few readings in the 5.5-5.7 (and I do mean only a few)
I have cut out bread, rice, pasta, potatoes and only eat strawberries and raspberries for fruit. I have no yogurt (which I miss) I do enjoy cheese and low sugar red wine, exercise every day (walking) yoga 2x/week, lost 14 lbs, sleep pretty well
I do take Humira for psoriasis but cannot find any documentation about affect on BS. Also take synthyroid for thyroid.
I still am in the pre-diabetes range. Not sure what else I can do and how long does it take to notice a difference when cutting out carbs?
Thanks
Lori
Lori
PS – I am a healthy weight and size as well
Elizabeth
Looks like you’ve been very intentional about working at diet changes which is awesome. I’d ask if you’ve amped up your activity (how much walking etc?) at all as this can make a significant difference as well. As far as how long it may take, it’s hard to tell as everyone is different, but following a healthy diet is win-win regardless of how long it may take–remember that sometimes diabetes is a combination of factors including a reduction in insulin being made so may require medication. It’d be hard to say whether there was any room for improvement without knowing all the details of what you currently do eat (rather than just what you’ve changed).
Lori
Thanks! I get at least 10,000 steps per day walking at 6km/hour pace.
Breakfast is an omelette with chedder cheese, lunch is salad with salmon or chicken with pumpkin seeds, a bit of cheese and oil/vinegar dressing. Other days I have salmon or chicken with grilled veggies (red pepper, asparagus) Dinner is the same as lunch (either salad or meat/veggies and wine.
I walk 3kms at lunch in 30 minutes and then again with my dogs after dinner. Plus moving around the office I easily get 10,000 steps
Any additional thoughts are appreciated!
Lori
John Hurskainen
I’m 140 to 160 mg every morning, every day. I’ve tested before I go to bed and been at 126 mg, tested in the middle of the night, been 112 mg but wake up at 157 mg. I average 166 mg in the morning when I get up after taking a shower. It starts to come down over the day then by dinner time I’m down to 88 to 105. I discussed with my Dr and have had my dose of Metformin cut in half for the evening dose to 500 mg (1 pill). Been doing that for 3 weeks now and still no change. I have also tried having just a protien shake and kale juice for dinner still the same. I even tried eating pizza for dinner and eating chocolate right before bed which has made no difference… So i wonder— am I broken??
Elizabeth
It sounds like Dawn Phenomenon–the idea that “stress” hormones start amping up around 4 am to prepare the body to wake up for the day. This happens to some degree in everyone, but more prominent in those with diabetes. It sounds like you’ve played around with your diet a bit, but that won’t necessarily address Dawn Phenomenon. Probably the best lifestyle change you can look to incorporate if you haven’t already is more exercise during the day. You won’t notice a direct or immediate effect, but regular daily exercise can help improve insulin sensitivity over time. Good luck.
Miky
Thank you all for your answers and encouragement I need it
I will keep up with the diet and exercise
Elizabeth the diet is from your site
I really enjoy it suits me perfect
Thank you
Elizabeth
You’re welcome, I’m so glad you find our resources and information helpful!
Miky
And my A1c level went down from 9.7 to 7.1 which doc said is ok
My daily readings are between 8-13mmol/l
Am I panicking for nothing?
Elizabeth
That’s excellent improvement! Yes, please stop panicking. You should still be concerned about your levels and remember that diabetes is a lifelong condition you will need to keep on top of, but that is a lot of improvement. It’d be great if you could get your levels a bit lower, but you are out of the ‘immediate danger zone’ you were certainly in with those original values.
Miky
My doctor told me the max Metformin per day must not exceed 3000mg she told me if I think that my BS levels are high to take another tablet but with care not more than 3000mg
I didn’t try 3000 but noticed not much diff between 1500 and 2000
Not sure what’s going on
Thank u for reply Susan
Elizabeth
There is a pretty detailed article about metfomin over here: https://diabetesmealplans.com/7176/metformin-blood-sugar-levels-weight-side-effects/
It works by decreasing liver & muscle output of glucose. It doesn’t make the body make more insulin or bring sugar levels down directly. It’s very effective at what it does, but cannot do everything. It is not like insulin where the more you give, the more it will lower blood sugar.
Susan
Many of you use the mmol levels in describing your sugar levels, I see this when the Dr does A1C tests, otherwise my daily readings are measured between 60-300. Miky did your Dr prescribe 2000 mg/day, or are you self medicating? This is way higher then anyone’s in my family who all have type 2 Diabetes. My brother & I are the only ones on insulin now because we’ve both had heart attacks. Again as I said in my first post – EVERY ONE IS AN INDIVIDUAL AND REACT DIFFERENTLY .
GOOD LUCK & take care of your HEART.
Elizabeth
2,000 mg metformin is an appropriate dose level. Usually prescribed as 1,000 mg twice daily. Never take without your doctor’s awareness–this is not an OTC medication, it does require a physicians prescription.
Miky
I was recently diagnosed with diabetes (3 months) and struggle lowering my sugar levels. I am following the diabetes diet but still have in the morning 8.6 -9 mmol/l occasionally 7.6-7.9 but not less than that and take daily 2000mg Metformin.
it is a progress from 10-11mmol/l but still high
What can I do?
Elizabeth
Great job following the diet Miky! That’s a good first step. Are you exercising regularly? That’s one of the most helpful things in getting down morning levels. Also, have your sugars come down from where they originally were? If so, they may continue to come down, but it takes some time. Lastly, consider there is so much you can do lifestyle-wise, but there is a time and place for medications and if it has progressed to a certain degree, may not be reversible without them. Talk to your doctor about different options.
Skip
Aloha. the answer is yes it can cause your levels to fluctuate for awhile. This is very common after some type of surgery. Some medications during an illness and after a surgery can also effect your sugar levels. The sugar levels should stabilize as you get better and or off the medications.
Terri Sherrell
This was extremely helpful. Thank you so much.
Elizabeth
Glad you found it helpful–thanks for coming to the site!
Steve Hilton
I have a question which I haven’t seen addressed, yet. I work the night shift, and have for about 6 months or so. Does the body naturally “adjust,” and “switch” the “dawn phenomenon,” or is that hard-wired into the human body?
Elizabeth
Steve, that’s a VERY good question and one I don’t know is entirely answerable. There is a natural circadian rhythm in which the body biologically operates best in and generally that involves getting up with the sun and going down with it. Clearly we can override this to a degree and some people adjust better than others. The body is very adaptable and durable but does reach a limit in some. I think it will be different for different people.
Susan
My doctors have told me higher blood sugar levels are “normal ” during an illness or if you are experiencing elevated pain levels. This has been the case for me. But remember every one is different, especially when you’re ill keep monitoring your BS. I personally can’t eat a bedtime snack, it forces my fasting BS up. Remember you are an individual. Talking with a professional is good,but you’re your own best advocate.
Elizabeth
Yes–one way of stating it is that it is ‘normal’ to have ‘abnormal’ blood sugar levels when in illness or in pain. But keep in mind that doesn’t mean the elevation (esp if chronic) won’t take it’s toll. There is no need for most people to take a bedtime snack–that is older advice for those on some of the older insulins like NPH. Those on a basal bolus regimen often are better off without one.
Lori
Are the ranges listed for everyone, non-diabetic & diabetic?
Elizabeth
The blood sugar ranges are for everyone in that a person should strive for healthy glucose control regardless of their diagnosis; however a person with diabetes will have a more difficult time achieving goal ranges. Someone who is consistently falling outside the ranges likely has diabetes, even if it is not diagnosed.
Cherryl
Is it a common occurrence for blood sugar levels to be elevated during an illness?
Lisa Johnson
Yes. Illness, stress, injury, menstrual cycle….all that can elevate your blood sugar.
Elizabeth
Yes, Lisa is correct, illness is one of the many factors that can elevate blood glucose. It is important to monitor more frequently when you are sick.
Christy
I love protein shakes in the morning, I use a natural protein
Powder mixed with water or unsweetened almond milk. It as 20g protein, 4 carbs and 2 sugar.
No artificial sweeteners. It raises my sugar in the morning, can you tell m why, anything. I can do to make it work for me
Thank you
Patricia Knoll
My blood sugar in the morning Is always high no matter what I do
Sheronne
Since being diagnosed with type 2 diabetes my sleep pattern has drastically change. I go to bed early but am awake for almost the entire night. On waking my glucose level is usually 5.6 to 6.2. I also have decreased appetite. What could be the reasons for the above? I know I’m stressed because of the diagnosis but…..
Elizabeth
It could be stress, but it could also simply be the Diabetes itself. Since it’s a condition of hormonal dysregulation, that can affect your sleep. It could also be medication if you are on them. Metformin can decrease appetite.