Why Is My Morning Glucose Always High? (Dawn Phenomenon Explained)

You went to bed with good blood sugar. You didn't eat anything overnight. So why did you wake up with glucose in the 140s, 150s, or higher?

Welcome to the dawn phenomenon—one of the most frustrating (and misunderstood) aspects of diabetes.

What is the dawn phenomenon?

The dawn phenomenon is a natural surge in blood sugar that happens in the early morning hours (usually between 2 AM and 8 AM). It's caused by your body's internal clock, not by anything you did wrong.

Here's what happens: in the early morning, your body releases hormones like cortisol, growth hormone, and adrenaline to wake you up and give you energy for the day. These hormones tell your liver to release stored glucose into your bloodstream.

For people without diabetes, insulin kicks in to handle the extra glucose. But if you have diabetes, your body can't respond as effectively—so your blood sugar stays elevated.

Is this normal?

Yes. The dawn phenomenon happens to most people with diabetes, especially Type 1 and insulin-dependent Type 2. It's not a sign that you're failing—it's just how your body works.

How is it different from the Somogyi effect?

The Somogyi effect (also called rebound hyperglycemia) is when your blood sugar drops too low overnight, and your body overcorrects by releasing a flood of glucose. This also causes high morning readings, but the cause is different.

To tell them apart, check your blood sugar around 2-3 AM. If it's low, it's Somogyi. If it's rising steadily, it's the dawn phenomenon.

How to manage high morning glucose

1. Eat a low-carb dinner

Heavy, carb-rich dinners can keep your blood sugar elevated overnight. Try lighter evening meals with more protein and vegetables.

2. Exercise in the evening

A walk after dinner can lower your overnight blood sugar and reduce the morning spike. Even 15-20 minutes helps.

3. Avoid late-night snacks

Eating right before bed raises blood sugar overnight. If you must snack, choose protein or fat (nuts, cheese) instead of carbs.

4. Adjust your medications

If you take insulin or medications, talk to your doctor about timing or dosage changes. Some people benefit from taking long-acting insulin at bedtime or adjusting their evening dose.

5. Manage stress and sleep

Poor sleep and stress raise cortisol, which worsens the dawn phenomenon. Aim for 7-9 hours of quality sleep and practice stress management techniques.

6. Try intermittent fasting

Some people find that not eating breakfast (or eating later in the morning) helps lower fasting glucose. Talk to your doctor before trying this.

Final thoughts

High morning glucose is frustrating, but it's manageable. Track your patterns, experiment with different strategies, and work with your doctor to find what works for your body.

Remember: you're not doing anything wrong. Your body is just being a body.