What is the difference between hyperglycemia and hypoglycemia?

One 2 hi, one 2 low. If u fast for 8 hours (FBS) blood sugar should be between 70 and 100. Hypo=low, hyper=high, glyc=sugar, emia=in the blood. If ur FBS is repeatedly between 100-126, you are in a state known as 'impaired glucose tolerance'. If ur FBS > 126, you are diabetic, which is by far the cause of hyperglycemia. Hypoglycemia usually is caused by too much Insulin in blood, or too strong rx of diabetes.