High blood sugar is a form of disease, usually there is no primary high blood sugar, but other diseases lead to high blood sugar. The most common disease is diabetes, a typical manifestation of diabetes is high blood sugar. Of course, there are many other reasons, such as: a significant reduction in physical activity, insulin does not work effectively. There are also many other causes, such as a significant reduction in physical activity, failure of insulin to work, excessive intake of sweets or sugar-containing beverages, excessive obesity, emotional or mental stress, alcohol consumption, or the use of certain medications. Generally speaking, high blood sugar can be eliminated if the cause of the disease is removed in time, and it can be restored after reducing the intake of sugar if it is consumed in excess. However, diabetic hyperglycemia is very difficult to treat.