The Dawn Phenomenon

The dawn phenomenon can lead to an elevated blood glucose (sugar) level in the morning.

The dawn phenomenon is a natural process that occurs at the end of a night’s sleep when your body releases hormones, such as cortisol, adrenalin and growth hormone, to prepare the body for awakening, among other tasks. These hormones have a counter-regulatory action on insulin, and they encourage the liver to secrete glucose, both of which can increase the level of blood glucose (sugar).

Thus, it is possible to wake up in the morning with an elevated blood glucose (sugar) level even though it was within target values when you went to bed on an empty stomach.

Your medication might need to be adjusted to correct this problem. If so, discuss this with your doctor.


Research and text: Diabetes Québec Team of Health Care Professionals

June 2014 (updated on August 2018)

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