Ok Well I Have Not Felt Good For 5 Years

ok well I have not felt good for 5 years The other day I was at my dr for swollen ankle she gave noticed how swollen I was she gave me predisone I feel great all the swelling is gone the dry icthy skin is gone my cuts are healing my eyesight is not blurry the rash on my face is gone I am not tired anymore. what can cause all these symptons