Short tem complications of diabetes, also called acute complications, can be:
fatigue, polyuria (need to urinate very often), blurry vision, ketoacidosis (break down of fatty acids), hyperglicemia, infections, polydipsia (always thirsty).
All this symptoms are because the glucose that we get from our diets it's not going to the cells, like it should. Instead, it stays in the blood and the cells don't recieve the energy they need, resulting in fatigue of the person.