There are 8 major hormones that affect the blood sugar levels. Insulin is the only one of these that curbs the levels of glucose. The others, namely, ACTH (Adrenocorticotropic Hormone), Cortisol, Glucagon, Growth hormones, Somatostatin, Thyroxine and Epinephrine boost the glucose levels as the body's reactions to certain specific incidents. This is usually nothing serious as it is a mere reaction of the body, and glucose levels drops down after a while.