How to Fix High Morning Blood Sugars Dawn Phenomenon and Reactive Hypoglycemia (Somogyi Effect)


There are various possible causes of a high blood sugar level in the morning:

1.The Dawn Phenomenon which is a natural rise in blood sugar due to a surge of hormones secreted at night which trigger your liver to dump sugar into your blood to help prepare you for the day.

2.Having high blood sugar from the night before which continue through the night into the morning.

3.Reactive hyperglycemia which is also called the Somogyi Effect. This is when a low blood sugar in the middle of the night triggers your liver to dump sugar into your blood in an attempt to stabilize your blood sugar.

Reactive Hypoglycemia (Somogyi Effect)

This is also known as rebound hypoglycemia or the Somogyi Effect. If when you test in the middle of the night you find your blood sugar is going low,

Your body is essentially in panic mode and alerts you by secreting counter regulatory hormones like glucagon and epinephrine (adrenaline) which trigger the liver to change its reserves of glycogen into glucose.

In short, your body senses a low blood sugar and dumps as much sugar as it can into the blood in an attempt to get enough fuel to function.

TheSomogyi Effect is less common than the Dawn Phenomenon, according to an article published by The Polish Journal of Endocrinology.

To diagnose either of these phenomena, scientists recommend checking blood sugar levels for several nights specifically between 3 a.m and 5 a.m. or using a continuous glucose on monitering system (CGM)

Here are some things you could try to reduce this occurrence:

•Eat a carbohydrate snack before bed.

•Reduce blood sugar-lowering medication or insulin in the evening.

•Reduce your long-acting insulin dose.

•Change your exercise schedule from afternoon or evening to first thing in the morning.

Make sure you don’t ignore reactive hypoglycaemia .Over time, your body’s response to low blood sugar levels may change due to hormone changes, leaving your body unable to warn you with low blood sugar symptoms and unable to trigger the liver into dumping sugar into your blood. Also, if other low blood sugar episodes have occurred earlier the same night or excess exercise has taken place, the liver may have already depleted its reserves of glycogen and may not be able to secrete glucose and raise your blood sugar

.This is why being aware of what is happening and solving the likelihood of this event is important. Some people with diabetes periodically check their blood sugar levels around 3 a.m. to stay aware of nighttime blood sugar trends.


The Dawn Phenomenon

The Dawn Phenomenon refers to a surge of hormones excreted by your body in the early morning hours. These hormones rise each night around the same time to prepare your body to wake.

Basically, your body is starting the engine, releasing some fuel, and prepping to go for the day .The Dawn Phenomenon occurs in all humans regardless of whether they have diabetes. However, many people with diabetes also experience a rise in blood sugar.

In people without diabetes, the body’s natural insulin response prevents the blood sugars from rising. These hormone surges affect those with type 1 diabetes and according to an ADA published journal, about half of people with type 2 diabetes.

Scientists have suggested that the Dawn Phenomenon experienced by those dependent on insulin is mostly caused by a surge in night time growth hormone secretion. Other hormones secreted in this surge include cortisol, adrenaline and glucagon. These hormones trigger the conversion of the liver’s glycogen stores into glucose which is then dumped into the blood in a process called glycogenolysis.

The Mayo Clinic suggests several things that you can try to combat the effects of the Dawn Phenomenon:

•Avoid carbohydrates at bedtime.

•Adjust your dose of medication or insulin. (If you take a long-acting insulin such as Lantus, be aware it doesn’t last a full 24 hours. This means you may want to try taking it at night or splitting the dose by taking half in the morning and the other half 12 hours later.)

•Switch to a different medication.



Many people get overly concerned about dawn phenomenon. If most of your night is spent with normal blood sugars and you experience a small, temporary increase in the morning, this is likely nothing to worry about. For those that are otherwise in target range, the morning increase is often less than they experience during a typical meal and even more short-lived.

Due to the Dawn Phenomenon, people are more resistant to insulin first thing in the morning. You may want to limit carbohydrates during the hour or two after you wake up. Insulin-users may need to have a higher insulin-to-carb ratio and take more insulin in the morning than during other parts of the day.

If you are experiencing high blood sugar in the morning as a result from elevated blood sugar from the night before, there are several things you could try:

•Eat fewer carbohydrates during the evening hours.

•Add evening exercise like an after-dinner walk.

•In consultation with your doctor, increase blood-sugar lowering medication or insulin.


20 Replies

  • The CGM helps during the night hours for me personally since I sometimes can't tell if I'm dropping. It's one reason why I got the DEXCOM G4 Platinum with Share in the first place. It's been a year since I first started using the system.

    Lantus is used mostly for people before bed since it's a long acting insulin. The directions for using that one brand of insulin says not to mix it with another insulin at the same time. How do you split taking half of the dose in the morning and the rest at bed?

  • Hi Activity2004 Even after being on Insulin for a year if your BS is unpredictably fluctuating, why not give a try to LWMDR? Initially it works as a support therapy to Insulin/tablet treatment. You will see difference in 2 - 3 months.


  • Thank you, but what is LWMDR? I personally never heard of it. What does it stand for? How does it work?

  • LWMDR is the abbreviation of "Long Wheat Mash Diet Regimen". Even though lakhs of people have seen online article, blog post and discussions here on LWMDR, I am aware of the fact that this number is an infinitesimaly small portion of the global population and hence the statement that you personally never heard of it didn't surprise me.

    It brought down FBS, PPBS & HbA1c to normal values and retained there even after restarting sweet and fruit intake. I have published photocopy of my recent lab report here which shows that all tested parameters including FSI are within range.

    Many members of HU/DI who followed LWMDR have reported positive/encouraging results.

    A published scientific study also have shown the positive effect of Long Wheat Diet.

    Even though same thing may not produce same/similar result in everyone world over, feedbacks so far indicate that it will work positively in majority of cases.

    Thank you for giving me an opportunity to tell this.

  • What does person who is on a gluten free diet do? I don't eat wheat products.

  • No solution suit everyone.

  • I have not seen a reply for this but do agree with Activity I also have the DEXCOM and have had mine for nearly 2 years.

    I have have never heard of splitting long acting dosages of insulin. I can take my long acting with short acting which is Levemir(LA). My dose is taken at noon I'm very subject to very low blood sugars during the night. Moving my dosage has helped significantly.

  • I do not know mixing long acting with short acting insulin.i understand long acting insulin works 12 hours from time of injecting.and hence you have to repeat every 12 hours.Consulting a doctor may resolve the issue.raised by you

  • Not all Diabetics are the same. Doing the same thing may not be okay for everyone else. Not everyone can split taking a certain type of medication or dose of insulin. It depends on the person who has to use it.

  • I have seen my cousin brother taking a portion of "plain" & another portion of "lent" insulins into same syringe and injecting. Plain Insulin bottle had white and lent insulin bottle had blue wrappers. This was during the 1960's. Those days I was an school student and my cousin brother was my headmaster.

    To my query that what is the difference it was clarified that plain one acts immediately where as lent starts acting slowly and hence acts longer. These are first hand information.

  • Things have changed in 50 years. Please talk to your Endocrinologist ShooterGeorge.

  • Yes, it's true - things have changed A LOT in 50 years. Thank you for the valuable advice. Unfortunately I am not diabetic any more; I fixed it for myself!

  • I believe you need to consult it may not- long acting for insulin. I would like to see your proof.

  • my proof is what i am doing under the advise of endoctrologist. I take human mixtard (30/70)which is a a combination of 30%short acting and 70% long acting at7 a.m in the morning 15 units before br fast and again at 7 pm 8 units before dinner.As activity 2004 says this may not work for all.

  • Thank you, ragivrao for saying about the advice under an Endocrinologist's care. My Endocrinologist wants me to do my long acting shot just at bed time. How effective would it be if it was split into two times a day? Would it still do its job correctly?

  • What basal insulin do you use?

  • Lantus before bed and Novolog during the day.

  • As you have all agreed, medication regimens vary quite a lot for people with insulin treated Type 1 and Type 2 diabetes. Some people, especially newly diagnosed are on twice a day injections of mixed long and slow acting insulin. Others are on multiple daily injections (MDI). I have Type 1 diabetes. I inject my rapid acting Humalog insulin every time I eat. I carb count and dose adjust depending on what the meal or snack is. I can also do corrective doses. It's not unusual for me to have 5 -8 injections of Humalog a day. My basal insulin is Levemir. I know from the advice of my diabetes consultant that it lasts around 12 hours in my system, so I split the dose and take 18 units at 8am and 18 units at 8pm. This means I get an overlap and constant presence of basal insulin in my system. If I took one daily dose of my Levemir it would run out way to soon and my blood-glucose levels would rise, possibly resulting in ketones.

  • That's right, but some insulin brands say not to let other insulins be mixed/over lap, unfortunately.

  • That's why it's always important to have a good and interactive dialogue with your diabetes healthcare team, ask them questions, engage with them and take an active interest in steering your own care and management options.