For people who have diabetes, the Somogyi effect and the dawn phenomenon both cause higher blood sugar levels in the morning. The dawn phenomenon happens naturally, but the Somogyi effect usually happens because of problems with your diabetes management routine.
Insulin, Blood Sugar, and Sleep
While you sleep, your body doesn’t need as much energy. But when you’re about to wake up, it gets ready to burn more fuel. It tells your liver to start releasing more glucose into your blood. That should trigger your body to release more insulin to handle more blood sugar.
The Dawn Phenomenon
If you have diabetes, your body doesn’t release more insulin to match the early-morning rise in blood sugar. It’s called the dawn phenomenon, since it usually happens between 3 a.m. and 8 a.m.
The dawn phenomenon happens to nearly everyone with diabetes. But there are a few ways to prevent it, including:
- Don’t eat carbohydrates before you go to bed.
- Take insulin before bedtime instead of earlier in the evening.
- Ask your doctor about adjusting your dose of insulin or other diabetes medicines.
- Use an insulin pump overnight.
The Somogyi Effect
The Somogyi effect also causes high levels of blood sugar in the early morning. But it usually happens when you take too much or too little insulin before bed, or when you skip your nighttime snack.
When that happens, your blood sugar can drop sharply overnight. Your body responds by releasing hormones that work against insulin. That means you’ll have too much blood sugar in the morning. It’s also called rebound hyperglycemia.
How Do You Know Which One You Have?
Your doctor will want to find out why you’re waking up with high blood sugar before they tell you how to treat it. This means they’ll ask you to test your blood sugar in the middle of the night -- around 2 or 3 a.m. -- for several nights.
If your levels are always low during that time, it’s probably the Somogyi effect. If not, it’s likely the dawn phenomenon. Knowing which is which will help your doctor come up with a plan to address it.