What Is Dawn Phenomenon In Diabetes – Sleep And Diabetes Advice

Everyone has a dawn phenomenon. But what is dawn phenomenon in diabetes, are your blood sugar levels high in the mornings.

Are you experiencing the Dawn Phenomenon?

High Glucose readings in the morning? What causes your glucose to be higher in the morning even if you haven’t eaten all night? Perhaps the answer could be the Dawn Phenomenon.Dawn Phenomenon in diabetes

Dawn phenomenon, is an early-morning (usually between 4 a.m. and 8 a.m.) increase in blood sugar. Everybody has dawn phenomenon but people without diabetes release insulin to handle the extra glucose burdening the bloodstream, diabetics however wake with high blood sugar levels. This can be a significant challenge to wake up to, as a diabetic is incapable of generating insulin in response to these glucose spikes.

Why Does It Happen

The dawn phenomenon is a natural function that takes place overnight while you are sleeping. Your body releases hormones ready for you to wake, these hormone cause insulin resistance, causing blood sugar to rise. This surge of new hormones then signals for the liver to make even more glucose to maintain a balance so we have enough energy to get out of bed.

In people with diabetes, this sugar release often occurs when there is not very much insulin in the body. As a result, the blood sugar starts to rise

The hormones that promote glucose release into the blood include:

Hormones In Diabetes

  • Adrenaline: Known as the “fight or flight” hormone, adrenaline increases blood flow to the muscles and promotes the release of glucose into the blood.
  • Cortisol: Known as the “stress hormone”, cortisol also plays a role in increasing blood glucose.
  • Glucagon: Signals the liver to release glucose into the blood.
  • Growth Hormone: Important for repair and regeneration and promotes the release of glucose into the blood.

High morning blood sugar may also be caused by insufficient insulin the night before, insufficient anti-diabetic medication or too many carbs before bed.

Experts disagree on how many people have a dawn phenomenon. Estimates range from 3% to 50% of Type 2s and from 25% to 50% of Type 1s.

How Do I Know If I Have Dawn Phenomenon

In addition to testing your blood sugar three to four times a day, sometimes set your alarm to wake up and test your blood sugar overnight, around 3 AM. If your blood sugar is good and stable between bedtime and 3 AM, but rises by the time you wake up, then you may have dawn phenomenon.

How To Manage The Dawn Phenomenon

Some steps people with diabetes can take to manage the dawn phenomenon include:

  • changing medication entirely or making adjustments with a doctor on existing medication
  • avoiding skipping meals or medication doses
  • avoiding high carbohydrates around bedtime. Eat something that is a slow release carb.
  • taking medication closer to bedtime and not at dinner time
  • get a good night of sleep—6 to 8 hours each night—and go to bed before midnight to help reduce cortisol and improve one’s ability to tolerate glucose.3
  • Eat dinner earlier in the evening and avoid late night snacks to reduce blood glucose in the evening.
  • Have your last meal of the day contain the least amount of carbohydrates to minimize the rise in blood glucose.
  • Do something active after dinner, such as a walk, to help lower blood glucose.
  • Eat a breakfast a lower in carbohydrates since blood glucose is high and you have greater insulin resistance in the morning.
  • Don’t wait too long to eat breakfast when you wake up. Eating food early in the morning can help release insulin which can lower blood

Some people have high glucose levels in the morning because their medicines wear off overnight. You may benefit from taking your metformin later in the evening, for example.

In some cases, medicine can be too strong. If your glucose goes too low in the night, you could have a rebound high in the morning. This is called the Somogyi effect. If you are waking up high and are suffering pounding headaches, really thirsty or find your sheets sweat-soaked, the odds are you are having lows in your sleep…You need to visit with your doctor about taking fewer meds. New insulins are much less likely to cause a Somogyi reaction. But because of cost, people are going back to NPH insulin. NPH is cheaper, shorter-acting, and more likely to cause a low, leading to a rebound high in the morning.

Is Dawn Phenomenon Dangerous

It can be serious for diabetics. According to the American Diabetes Association, some people with dawn phenomenon find that their glucose continues to rise until they eat in the morning. For others, levels will settle down a few hours after waking, regardless of whether they eat.”

Either way, that can be a long time to spend with high blood glucose levels. People who experience repeated high blood sugar levels due to dawn phenomenon should see a doctor to prevent diabetic complications.


In conclusion, failing to address the dawn and extended dawn phenomena can contribute to inadequate overall blood level control and increase the risk for development or progression of diabetes complications. If you think you are having the dawn phenomenon, its important to speak to your medical team for the best options to help.

Please leave any comments or questions below, I will try to respond within 24 hours


Garry (Type 1)

Garry type 1 diabetic


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