Dawn Phenomenon and Diabetes: All You Need to Know

In the morning, body prepares to rise and liberates a rush of hormones. Those hormones may act against insulin. And, this results in slight rise in the levels of blood sugar. It is referred to as the ‘dawn phenomenon.’ This phenomenon is naturally harmless in many people as their body produces a small quantity of insulin to rectify the issue. Yet, for diabetics, it may turn as a bigger challenge. If a person is diabetic, it is important for them to understand how to control blood sugar at night. So, that they don’t need to be anxious about managing it in the morning.

What Causes Dawn Phenomenon?

For diabetics, dawn phenomenon is challenging. As, their body is not capable of naturally rectifying the insulin modifications throughout the night. This produces constantly high blood sugar levels in the morning. This phenomenon is found to occur in 50% of type 2 diabetic population.

The dawn phenomenon is also known as the “dawn effect”. In thus, the blood glucose spikes around the hours of waking, approximately between 4 to 8 AM. The exact reasons for this are still not clear. Still, it is known that hormones play a huge role. These may include adrenaline, growth hormone, cortisol, and glucagon. These hormones follow a circadian cycle. And, they are present in higher concentrations in the blood in the morning. This helps a person get ready for the day ahead.

Dawn Phenomenon: What It Is, Causes & How to Fix It

Hormones that support the release of glucose into the blood may be:

  • Growth Hormone: Vital for renewal and regeneration. Also, it supports the release of sugar into the blood.
  • Adrenaline: It is the “fight or flight” hormone. And, it increases blood flow to the muscles and supports sugar liberation into the blood.
  • Cortisol: It is the “stress hormone”. Also, it increases the release of glucose into the blood.
  • Glucagon: Directs the liver to liberate sugar into the blood.

There are two important processes that take place in the liver overnight. And, these causes the release of sugar into the bloodstream. Also, they add to an increased morning blood sugar:

  • Glycogenolysis: which is the breakdown and liberation of stored glucose (or, glycogen).
  • Gluconeogenesis: production of sugar from constituents of protein (various amino acids) or fat (glycerol).

Low Blood Glucose at Night

If a person finds low glucose levels during the night, that is another problem. If a person notices it, it is known as the Somogyi effect. This occurs when there is a reduction in the levels of blood sugar during the night. And, a person’s body liberates hormones (including cortisol) to counteract this fall. This results in a higher-than-normal blood glucose rise.

Also Read: Hba1c normal range chart

Does Dawn Phenomenon Appear Only in Prediabetics and Type 2 Diabetics?

The physiological processes that trigger this phenomenon happen in every person irrespective of the occurrence of diabetes or not. The difference lies with insulin and how people respond to it. Healthy people make enough insulin. Also, they are insulin sensitive to respond to a spike in morning blood sugar. Yet, any person having prediabetes or type 2 diabetes is insulin resistant and might not form enough insulin, which increases blood sugar. This might be further combined in the early morning hours. As people are more insulin resistant in comparison to the rest of the day. This causes a raised fasting sugar to remain elevated longer. Development of prediabetes and type 2 diabetes causes worsening of the dawn phenomenon. This is because the insulin function and sensitivity carry on diminishing.

Effect of the Dawn Phenomenon

Signs of the dawn phenomenon may involve nausea, fatigue, and intense thirst. The dawn phenomenon is an increase in the blood glucose liberated by the liver. The liberation occurs as an individual’s body is getting ready to wake for the day. The body usually utilizes insulin to deal this spike in blood glucose. The body of a diabetic patient fails to form enough insulin. Or, it is incapable of using the insulin in a proper way. Consequently, person would experience the effects of having high glucose levels in the blood. These effects may be:

  • nausea
  • vomiting
  • hazy vision
  • faintness
  • fatigue
  • intense thirst
  • weakness
  • disorientation

Is the Dawn Phenomenon Requiring Fixing?

This phenomenon is not essentially something that requires fixing. It’s vital to remember that even if a person’s fasting sugar is increased, he or she might have lower or normal sugar values all over the day. Moreover, it’s not rare for patients reversing their diabetes via nutritional ketosis to experience the dawn phenomenon and still notice improvements in their HbA1c. Why? As HbA1c is an evaluation of the blood sugar over the last 3 months. The average value matters more than any person’s sugar value.

Management of Dawn Phenomenon

Management of glucose levels is vital for diabetic patients. An individual whose blood glucose levels are regularly above 180 mg/dl must look for medical help. As, this might cause complications. A blend of diet, exercise, and medicine might aid in keeping the signs under control. Also, it avoids the development of complications. In the case of this phenomenon, few changes might aid preventing the issues from increasing the blood sugar.

There are a few steps diabetics can take to manage the dawn phenomenon. And, these include:

  • consuming regular meals.
  • consuming all their medicine doses.
  • discussing with a healthcare provider about altering or regulating their medicine.
  • preventing carbs around bedtime.
  • performing light physical activity after dinner. These may include going for a walk, jogging, or yoga.
  • consuming medicine near to bedtime instead of dinner time.
  • consuming dinner earlier in the evening.

If blood glucose levels are high from time to time, this is not too troublesome. Yet, if it happens often, an individual must discuss with a doctor.

How to Fight the Dawn Phenomenon? Will Lowering My Carb Consumption Help?

If a person wishes to understand if raised morning blood sugar numbers are a result of the dawn phenomenon or from excessive dietary carbs, all he or she needs to do is test multiple times during the day. Most importantly, a person must be familiar with what fasting sugar looks like. Whether it be the most current lab values from the physician or checking sugar using a meter, the best way to know where the fasting sugar falls is to evaluate it and to test it on some diverse days.

Likewise, blood sugar testing is vital during the day, before and after meals. And, before a person goes to bed helps a person understand how the body reacts to the food a person consumes. Once a person has tested enough that he or she understands the baseline sugar with current habits, try adding each of the approaches into his or her routine. Carry on blood sugar testing and see what effects each change has on your morning fasting sugar values.

Approaches that might aid in mitigating this Dawn Phenomenon:

  • Decrease the overall carb consumption to reduce blood glucose.
  • Consume dinner earlier in the evening. Also, avoid late-night snacks to lower blood sugar in the evening.
  • Get a good night of sleep i.e., 6 to 8 hours every night. And, go to bed prior to midnight to help in lowering cortisol. Also, it might improve a person’s capacity to tolerate glucose.
  • Consume the last meal of the day to reduce the spike in blood sugar. This reduces the least amount of carbs.
  • Be physically active after dinner including a walk. This helps in reducing blood sugar.
  • Consume a breakfast with a reduced number of carbs. Since blood sugar is high and he or she has a higher insulin resistance in the morning.
  • Don’t wait too long to have breakfast when a person awakens. Consuming food early in the morning helps in liberating insulin which may reduce blood glucose.


Does intermittent fasting aid in this phenomenon?

The dawn phenomenon directly associates with insulin sensitivity or production. Improving insulin sensitivity via a low-carb diet and/or intermittent fasting, would lessen the morning fasting blood sugar values. Also, reduce the dawn phenomenon effect.

Can a person without diabetes have dawn phenomenon?

Plasma glucagon fails to alter considerably during the period of observation. These outcomes state that a dawn-like phenomenon, began by an enhanced sugar production, happens in nondiabetic people.

Does apple cider vinegar assist in dawn phenomenon?

Consuming a small amount (2 tablespoon) of ACV at night helps in lowering the blood sugar spikes in the morning. It effectively responds to the dawn phenomenon.


  1. https://www.virtahealth.com/blog/dawn-phenomenon
  2. https://www.medicalnewstoday.com/articles/317351
  3. https://health.clevelandclinic.org/dawn-phenomenon-know-diabetes/

Last Updated on by Dr. Damanjit Duggal 


This site provides educational content; however, it is not a substitute for professional medical guidance. Readers should consult their healthcare professional for personalised guidance. We work hard to provide accurate and helpful information. Your well-being is important to us, and we value your feedback. To learn more, visit our editorial policy page for details on our content guidelines and the content creation process.

Leave a Reply

Download Free Diabetes Diet Plan