What Is The Dawn Phenomenon?

Dawn Phenomenon - Type 1 Diabetes

If you have diabetes, you know the Dawn Phenomenon. Perhaps you haven’t been mindful of its occurrence, unconsciously adjusted for its presence, or have just thrown your hands up in the air in frustration. Before we get into the research behind its existence–close to 200 research articles have been published on this–let’s look at how this usually evolves in a diabetic day.

It’s 6am, or 9am in Amber‘s case. Your alarm goes off. It’s going to be best day ever. Your blood sugar is 120. After showering, doing whatever you term exercise in the morning, making your morning commute, you settle in at your desk. Before opening the email floodgates, you test your blood sugar. Boom. This happens. You’re above 200. To this point, nothing has changed in your routine. You ate the same breakfast. You’re not sick. Your pump is working fine. These are the three most common manifestations of the dawn phenomenon in my life:

1) I take the same amount of insulin for a number of carbs that I would normally eat at night, except that my blood sugar is now 250 mid-morning.

2) I eat no food. I do nothing athletic. I go to class in the morning. When testing my blood sugar a couple of hours after waking up, it’s 200.

3) I leave my house at dawn, go out for a 30 minute run. Don’t make any adjustments to my basal. My blood sugar is 190, after being 140 before.


So what is happening? Research has found the culprit. It’s night-time, 4AM or so, human growth hormone secretions. Every person has this happen to them. The body is trying to get us ready to seize the day. This human growth hormone stimulates the liver to break down our glucose stores, releasing it in the blood. Normal people can handle this fine with an uptick in insulin secretion. Us, well, we sometimes get a morning high blood sugar because of this process.

Does this happen to you? Feel free to share your own strategies. Has this never happened to you? Disregard the previous 300 words and go back to your day job.