When blood sugar is higher than normal, you are most likely to feel tired and hungry all the time even after having your meals. The food which we intake is converted into glucose by our body and that glucose gives us the energy to perform our daily tasks. This glucose is taken into cells when your body is making enough insulin. In case you have high sugar, your body does not create enough Insulin, making it difficult for the glucose to enter your body. This can result in making you feel more tired and hungrier. So, if you are feeling tired even after resting and taking a good eight hours of sleep, do not assume that you are lazy, you can be taking an irregular amount of sugar.