If the levels of Creatinine get high, it can indicate that his kidneys are not functioning well. Fatigue, swelling, and difficulty urinating are all symptoms connected with this. There could be many causes such as lack of fluids or even certain drugs he may be taking for these signs and symptoms which include tiredness, edema (swelling) around ankles or eyes as well as anuria. He needs however follow the advice given by his doctor very closely for them to get better.