Diabetes mellitus refers to a group of diseases that affect how your body uses blood sugar. The underlying cause of diabetes varies by type. But no matter what type of diabetes you have, it can lead to excess sugar in your blood. Too much sugar in your blood can lead to serious health problems.
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 could be disabling or even life-threatening.
Some people with diabetes experience an abnormal early-morning increase in blood sugar, or glucose — usually between 2 and 8 a.m. This is called the "dawn phenomenon," or "dawn effect."
Some researchers believe the natural overnight release of the so-called counter-regulatory hormones, including growth hormone, cortisol, glucagon and epinephrine, increases insulin resistance, causing blood sugar to rise. High morning blood sugar also may be caused by insufficient insulin the night before, insufficient anti-diabetic medication doses or carbohydrate snack consumption at bedtime.