»  News
 »  Facing the Challenge of Dawn Phenomenon
Diabetes1 Headlines

Facing the Challenge of Dawn Phenomenon

Printer Friendly Version     Email this Article     Links/Reprints

Facing the Challenge of Dawn Phenomenon

Facing the Challenge of Dawn Phenomenon

October 30, 2008

By: Doris Dickson for Diabetes1


Dawn phenomenon is the term used to describe an abnormal early-morning increase in blood sugar normally between 4 a.m. and 8 a.m.  It is most pronounced in type 1 diabetics, whose insulin must be injected entirely on a manual basis or with an insulin pump.


What causes dawn phenomenon?


Researchers still do not entirely understand the mechanics of dawn phenomenon. However, there are four primary hypotheses:


·         Nocturnal spikes in hormone secretion including growth hormone, cortisol, glucagon and epinephrine

·         Reduced utilization of glucose by insulin-dependent tissues, such as muscle tissue

·         Overproduction of glucose by the liver

·         The deactivation of insulin by the liver


The result is an increase in blood sugar and often insulin resistance in many diabetic patients between approximately 4 and 8 a.m.


What is a rebound (the Somogyi Effect)?


According to the National Institutes of Health, the Somogyi effect is defined as a fasting hyperglycemia that occurs after inducement of nocturnal hypoglycemia by regular insulin.


However, many diabetics experience a blood sugar rebound after a moderate or severe hypoglycemic event, not just those that occur while sleeping. The blood sugar level at which a diabetic experiences a “rebound” varies. Both insulin dependent and some medication dependent diabetics are susceptible to low blood sugar and thus, are susceptible to a blood sugar “rebound.”


Do you have dawn phenomenon?


Insulin-dependent diabetics can determine whether they are experiencing dawn phenomenon by performing basal testing in order to rule out other potential culprits such as:


·         The Somogyi effect

·         Delayed food digestion

·         An improper basal setting or insulin waning


A basal test is frequent glucose testing (e.g. every two hours) while eliminating other variables such as food, bolus insulin injections, stimulants such as caffeine, exercise, etc. After accumulating the data, you will be able to see when or if you start to see an increase in early morning blood sugar attributable to the dawn phenomenon. 


You may also observe whether your overnight basal rates are set too high or low. If your blood sugar is high, you may consider an increase in your basal or long-acting insulin. If your blood sugar is low, you may consider a decrease in your basal or long-acting insulin. If you are not completely comfortable with adjusting your insulin doses, you can ask your CDE or doctor for assistance.


Preventing dawn phenomenon


  • Add a small amount of NPH to your regimen just before bedtime to correspond to the prospective increased blood sugar.
  • Move your long-acting insulin injection from dinner to bedtime.
  • Rise early enough in the morning to test your blood sugar and ward off the impending increase by using rapid acting insulin as needed.
  • Invest in an insulin pump to enable setting multiple insulin needs in conjunction with daily blood sugar testing.
  • Decrease consumption of foods that are known to increase blood sugar (e.g. carbohydrates and caffeine) to reduce insulin needs.
  • Exercise to increase insulin sensitivity.
  • Eat a small protein snack before going to sleep.
  • Discuss an agent such as metformin (to increase insulin sensitivity and reduce glucose release by the liver) with your medical provider.


Dawn phenomenon is a challenge for many diabetics. As with anything related to diabetes, diligent self-management including blood sugar testing continues to be the best means of alleviating the problem. In addition, talk with your medical provider regarding insulin or medication adjustments if necessary. 

Discuss Type 1 Diabetes in our Forums More Forums

Previous Stories

Understanding Low Blood Sugar

Keeping a Diabetes Log - How to and Benefits

Growing Old and Staying Healthy with Diabetes

more Feature Stories


  • Add Comment

  • RSS
    From the BLOGS
    Comment By ricvisa
    more Blogs
    By FatCatAnna

    Posted: Mar 17, 2017
     Thanks for that Andre77 ... though in this area where you've posted "Type 1 Diabetes" - we already know we've got diabetes (50+ years for me).   DiabetesUK has a pretty good description of ...

    more more Forums Create a Topic
    Lifestyle Change Emotion Part4
    Identifying Depression- Lifestyle Changes and Emotions
    The symptoms of depression...
    more more Featured Videos
    Cost Savings Tool
    Do you know the annual cost of managing your diabetes? Would you like to find ways to reduce your costs? Calculate your total budget and identify ways to save money. You can do this in just a few minutes by entering facts about the products you use. This quick analysis will provide you with a comprehensive overview of both spending and potential savings.

    Cost Savings Tool
    Monitor Comparison Tools
    Blood glucose monitors offer an easy way to test your blood sugar at home or on the go. Use this comparison tool as a guide to learn more about the features and benefits of your current monitor or to find a new one.
    Handheld Monitor Comparison
    Continuous Glucose Monitor Comparison
    Advanced BMI Calculator
    Ever wonder if you are at a healthy weight? Then enter your height and weight in our advanced Body Mass Index (BMI) calculator. This tool provides you with two important numbers reflecting the estimated impact of your present body weight and shape upon your overall health.
    Advanced BMI Calculator
    more Care Tools
    Dr. Wayne Caputo

    Dr. Wayne Caputo:

    Simplifying Treatment of Diabetic Ulcers
      more Heroes
      nominate a Hero
      Hero policy
    Home | About Us | Press | Make a Suggestion | Content Syndication | Terms of Service | Editorial Policy | Privacy Policy
    Last updated: Jul 20, 2019  © 2019 Body1 All rights reserved.