Dawn Phenomenon

Dawn phenomenon in people with diabetes

woman reaching for glass on nighstand
Increased thirst can be a sign of diabetes. Stockbyte/Getty Images

Dawn phenomenon is an event that sometimes happens to people with diabetes. It occurs more often in type 1 diabetes than type 2 diabetes. Dawn phenomenon causes a rise in blood glucose levels early in the morning before you wake up.

What is Diabetes?

Diabetes mellitus refers to a group of diseases that affect how your body uses blood sugar (glucose). Glucose is vital to your health because it's an important source of energy for the cells that make up your muscles and tissues.

It's also your brain's main source of fuel.

If you have diabetes, no matter what type, it means you have too much glucose in your blood, although the causes may differ. Too much glucose can lead to serious health problems.

Chronic diabetes conditions include type 1 diabetes and type 2 diabetes. Potentially reversible diabetes conditions include prediabetes — when your blood sugar levels are higher than normal, but not high enough to be classified as diabetes — and gestational diabetes, which occurs during pregnancy but may resolve after the baby is delivered.

Symptoms of Diabetes

Diabetes symptoms vary depending on how much your blood sugar is elevated. Some people, especially those with prediabetes or type 2 diabetes, may not experience symptoms initially. In type 1 diabetes, symptoms tend to come on quickly and be more severe.

Some of the signs and symptoms of type 1 and type 2 diabetes are:

  • Increased thirst
  • Frequent urination
  • Extreme hunger
  • Unexplained weight loss
  • Presence of ketones in the urine (ketones are a byproduct of the breakdown of muscle and fat that happens when there's not enough available insulin)
  • Fatigue
  • Irritability
  • Blurred vision
  • Slow-healing sores
  • Frequent infections, such as gums or skin infections and vaginal infections

    Although type 1 diabetes can develop at any age, it typically appears during childhood or adolescence. Type 2 diabetes, the more common type, can develop at any age, though it's more common in people older than 40.

    Complications of Diabetes

    Long-term complications of diabetes develop gradually. The longer you have diabetes — and the less controlled your blood sugar — the higher the risk of complications. Eventually, diabetes complications may be disabling or even life-threatening. Possible complications include cardiovascular disease, nerve damage (neuropathy), kidney damage (nephropathy), eye damage (retinopathy), foot damage, skin conditions, hearing impairment and Alzheimer's disease. Type 2 diabetes may increase the risk of Alzheimer's disease. The poorer your blood sugar control, the greater the risk appears to be. Although there are theories as to how these disorders might be connected, none has yet been proved.

    More on Dawn Phenomenon

    During the night, hormones may be released that trigger the liver to release glucose. If there is not enough insulin in the body to counteract this, then blood glucose levels rise during the night, resulting in the higher reading in the morning.

    It may be tempting to skip breakfast in an effort to bring down the glucose level, but not eating will not accomplish this.

    Eating breakfast allows blood glucose levels to return to normal by turning off the mechanism that is causing the liver to release glucose, thereby breaking the cycle. If no breakfast is eaten, then the blood glucose will continue to rise.

    For an in-depth look at dawn phenomenon,


    Kaufman, MD, Francine Ratner. "The Dawn Phenomenon." DOC News Vol. 3. Number 7. page 5. 01 Jul 2006 27 Nov 2007.

    Mayo Clinic. Diabetes. http://www.mayoclinic.org/diseases-conditions/diabetes/basics/definition/con-20033091

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