Normal level at bedtime (91), up 35 points in morning (145).

by Frances Rose
(Nashville, NC (USA))

QUESTION: Why is my Blood sugar 91 when I go to bed at night and 145 when I get up in morning? Nothing to eat or drink during night.

ANSWER: Hi Frances,

I understand your concern.

Your blood sugar at bedtime is completely normal (91 mg/dL). During the night, you are not eating or drinking anything.

In the morning, you find your blood glucose as high as 145 mg/dL.

Ok, there are 2 main explanations for this:

1. Morning hormones: they include cortisol, growth hormone, chatecholamines.
They get higher in early morning. They induce the production and secretion of sugar from liver with high blood glucose as consequence.

In non-diabetic people, this high blood sugar is associated with increased insulin production and secretion to lower it.

If cannot produce enough insulin, the result is having high morning blood sugar levels. This is called Dawn Phenomenon.

2. Somogyi effect: in early morning, blood sugar is very low as response to insulin.
Your body reacts by realeasing morning hormones to increase blood sugar.

When you measure early morning, you find your blood glucose raised.

Now, what I suggest to my patients is to measure their blood sugar levels in the first hours of morning (e.g. 2 to 3 a.m), and record the results.

If your blood sugar at this time is low, then, you get high blood sugar in the morning due to Somogyi effect.

This can be corrected by having a snack at bedtime.

If blood glucose is normal at 2 to 3 a.m, then, this is Dawn Phenomenon.

I'd suggest to measure HbA1C level to evaluate your blood sugar average within the last 3 months.

Hope this helps. Let me know if you have further queries.


Comments for Normal level at bedtime (91), up 35 points in morning (145).

Average Rating starstarstarstarstar

Click here to add your own Comment / Follow up

Jul 15, 2018
What type of Snack and how much?
by: Anonymous


The suggestion of a snack is made.

What type of snack and how much?

Thank you

Aug 21, 2018
Fasting sugar 120, PP 190, take sweets reaches 260
by: Kapil

HELLO: Hello sir,

My fasting sugar is 120 and pp is 190 . when I take sweets, it reaches 260 ...

Should I take medicines? Age is 42.


Oct 12, 2018

by: Dr.Albana

Hello Kapil,

I have gone through your sugar levels carefully and here's my answer.

It seems that your blood glucose spikes when eating sweets. In fact, there is alteration in blood sugar levels.

The next step is to run HBA1C test to determine the mean of your blood glucose within the last 3 months.

Next, at your age we should exclude metabolic and hormonal problems first.
So, should run various blood tests including:
- complete blood count
- thyroid function test
- liver/kidney/pancreas function test
- urine analysis
- blood electrolytes
- blood vitamins B, D, calcium levels

After evaluating the results, we can make the best treatment strategy.

For the moment, I can only suggest to make some changes in your diet and lifestyle regimen first.

Hope this helps. Looking forward to have the requested lab tests reports in.


Mar 23, 2019
Blood Sugar level - what is going on?
by: Athar


Two years ago my A1c was 6,5 which was a bit shocking given my diet and lifestyle. Well i realized that after dinner I have been eating lots of different fruits for long time and that maybe the reason.

I really enjoy eating fruits and veg so instead I started eating fruits during day and stopped eating at night after dinner. After 6 months had another check and A1c was 6. .

But something is strange now - if after dinner I don’t eat anything or just have a gram cracker or cookie with tea, in the morning blood sugar is 120-135 range.

However, if I eat indian sweet(seriously no joke) or ice cream (vanilla, mango), sugar level in the morning is lower, like 105, 110, 115 range.

I have done this experiment for months just to make sire and told my friends and relatives of this apprently unusable phenomenon.

And they are amazed but probably don’t believe me. I have talked with my Dr as well but just get bsck strange and puzzled look.

Does anyone have any suggestion or explanation for this condition?

Next month I will have another A1c to see if all is fine. Will post here.

ANSWER: Hello Athar,

There is nothing strange here. All what's happening to you is related to sugar metabolism.
Let me explain it in details:

When you have low glycemic or calories food at dinner, that won't cause increased blood sugar; instedad, they might cause drops of blood glucose during the night (we call this nocturnal hypoglycemia).

As the body tends to bring the blood sugar back to normal range during the night; it ends up with slightly elevated fasting blood glucose. This is mainly due to increased levels of glucagon.

Now, if you do consume high glycemic/calories foods, they will cause high blood sugar levels after eating, and during the night.

Meanwhile, your body is working more to bring these high levels back to normal ranges ending up with normal or slighly lowering levels due to insulin overproduction.

This is the only explanation. Looking forward to get your next HbA1C test result for comparison.

All the best. Let me know if you have any other concern.

Nov 06, 2019
Weird morning blood glucose readings
by: Bill V.


My bedtime blood sugar reading is usually around 109 or so. I retire at 10:00 PM. My morning glucose reading is usually between 68 and 103.

But as odd as it may seem - those numbers are only my usual on nights when I sleep all the way through.

If I get up to let the dog out (around midnight or 2:00 AM) my morning count goes way up to a 119 to 134 range.

I usually get up around 7:30 AM. Does getting up in the middle of the night make my blood sugar rise?

ANSWER: Hello,

I was reviewing your blood sugar levels before going to bed at night and when wakening, they seem perfectly normal.

With regards to slightly raised blood sugar in the morning after you've been waking up in the middle of the night to let your dog going out, that is not a weird situation.

Actually, I would like to ask you measure the blood sugar in the middle of the night at 2.00 am to 3.00 am or at the time you get up to let your dog out.

If the findings will be consistently low, then, it might be due to Somogyi effect. In other words, you might experience drops in blood sugar in the middle of the night. Your body reacts to increase blood sugar finishing up to slightly elevated blood glucose levels.

Looking forward to get the findings of your blood sugar levels.

Let me know if you have any other concern.


Click here to add your own Comment / Follow up

Ask the Doctor now? Simply click here to return to Diabetes Test and Levels.

Ask Diabetes Questions and get a reply from a real medical doctor