The sugar level means the amount of glucose in the. Glucose is the main energy source of the body. Glucose is absorbed fromt he food we consume. High glucose (high sugar), which is called hyperglycemia, occurs when the body cannot use glucose properly( type2 diabetes), or it has insufficient amounts of it (type 1 diabetes). If this condition lasts for months or years, it makes a permanently damage to certain organs such as kidneys, blood vessels, nerves, and eyes.