As morning approaches, your body prepares to rise and it releases a surge of hormones. Those hormones can work against insulin to cause your blood sugar to rise slightly. When this happens, it is known as ‘dawn phenomenon.’
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
In most people, dawn phenomenon is typically harmless because your body creates a small amount of insulin to correct the problem. However, for those with diabetes, it can become a bigger challenge, says endocrinologist Sana Hasan, DO.
If you have diabetes, here’s what you need to know about regulating your blood sugar at night so you don’t have to worry about managing it first thing in the morning.
How does dawn phenomenon work?
For people with diabetes, dawn phenomenon is problematic because your body isn’t able to naturally correct for insulin changes during the night. This often creates consistently high blood glucose levels in the morning. Estimates show that dawn phenomenon occurs in about 50% of people who have type 2 diabetes.
How you can help pinpoint the problem
If you find that your blood sugar is consistently high when you wake up, you can help diagnose the issue by checking your blood sugar levels during the night.
Dr. Hasan suggests that you set your alarm for 2 or 3 a.m. for a few nights in a row to see what the levels are like during that time. “If they’re high then, that’s probably a sign of dawn phenomenon,” she says.
Low blood sugar at night — a different problem
But if you find low blood sugar levels during the night, that’s another issue altogether. If this is the case, you likely have what is known as the Somogyi effect, or rebound hyperglycemia.
This happens when blood sugar drops during the night and your body releases hormones (including cortisol) to counteract this drop, causing a higher-than-normal blood sugar spike.
How to manage dawn phenomenon
There is a short list of things you can do on your own to help reduce morning blood sugar highs. The list includes:
- Take medication or insulin at bedtime instead of at dinnertime.
- Eat dinner earlier in the evening.
- Get some exercise after dinner.
- Avoid snacks that contain carbohydrates at bedtime.
If these don’t work, your physician may recommend:
- Trying a different medication.
- Moving from oral medication to insulin.
- Changing the type or dosage of insulin you take.
If you find that your blood sugar is consistently high in the morning or you see signs that it might be — sweating, intense hunger, lightheadedness, shaking or anxiety, or dramatic mood swings — it is important to talk to your doctor.
Managing glucose spikes is vital because even a small increase in blood sugar can greatly increase the risk of diabetes-related complications including heart disease, stroke and neuropathy (nerve damage).