The phrase ‘dawn phenomenon’ is used to describe an abnormal early-morning rise in blood sugar (glucose) in people with diabetes, often between 2 and 8 a.m.  According to some experts, the nightly release of the body's naturally occurring "counter-regulatory" hormones, such as growth hormone, cortisol, glucagon, and adrenaline, enhances insulin resistance and raises blood sugar levels. These high blood sugar levels are also known as hyperglycemia.