Why Your Blood Sugar Spikes at Dawn—And What You Can Actually Do About It

If you have diabetes and notice your blood sugar is consistently higher in the morning than when you went to bed, you're not alone. This frustrating pattern is called the dawn phenomenon, and it affects many people managing their blood sugar daily.

What Exactly Is the Dawn Phenomenon?

The dawn phenomenon is an early-morning rise in blood glucose that typically happens between 4 a.m. and 8 a.m. in people with diabetes. This surge leads to high blood sugar levels, a condition called hyperglycemia. The tricky part? It happens naturally, even if you haven't eaten anything overnight.

Why Does Your Body Do This?

Researchers believe the culprit is a group of hormones your body releases naturally during sleep. These hormones—growth hormone, cortisol, glucagon, and epinephrine—work against insulin's effects, a phenomenon called insulin resistance. When these counter-regulatory hormones flood your system in the early morning hours, your blood sugar climbs as a result.

However, the dawn phenomenon isn't always just about hormones. Sometimes high morning blood sugar happens because you didn't get enough insulin the night before, took the wrong dose of diabetes medicine, or ate a carbohydrate-containing snack at bedtime.

How to Know If You Have It

If you suspect the dawn phenomenon is affecting you, talk to your healthcare provider. They may ask you to check your blood sugar once during the early-morning hours for several days in a row, or they might recommend using a continuous glucose monitor to track your levels while you sleep. This data helps confirm whether you actually have the dawn phenomenon or if something else is causing your morning highs.

Practical Solutions Your Doctor Might Suggest

The good news? There are several evidence-based strategies to prevent or correct high morning blood sugar. Your healthcare provider may recommend:

• Avoiding carbohydrates at bedtime
• Changing your dose of diabetes medicine or insulin
• Switching to a different diabetes medicine altogether
• Taking your medication or insulin at bedtime instead of dinnertime
• Using an insulin pump to deliver extra insulin during the early-morning hours

The best approach depends on your individual situation, so working closely with your healthcare team is essential. What works for one person might not work for another, and your provider can help you find the strategy that fits your lifestyle and diabetes management routine.