The dawn phenomenon and the Somogyi effect cause high blood sugar levels, especially in the morning before breakfast, in people who have diabetes.
Dawn phenomenon
The dawn phenomenon is a normal rise in blood sugar as a person's body prepares to wake up.
- In the early morning hours, hormones (growth hormone, cortisol, and catecholamines) cause the liver to release large amounts of sugar into the bloodstream. For most people, the body produces insulin to control the rise in blood sugar.
- If the body doesn't produce enough insulin, blood sugar levels can rise. This may cause high blood sugar in the morning (before eating).
Somogyi effect
If the blood sugar level drops too low in the early morning hours, hormones (such as growth hormone, cortisol, and catecholamines) are released. These help reverse the low blood sugar level but may lead to blood sugar levels that are higher than normal in the morning. An example of the Somogyi effect is:
- A person who takes insulin doesn't eat a regular bedtime snack, and the person's blood sugar level drops during the night.
- The person's body responds to the low blood sugar by releasing hormones that raise the blood sugar level. This may cause a high blood sugar level in the early morning.
