It depends what you consider low. A replacement dose of cortisone is about 5mg of Prednisolone a day. Anything above this leads to side effects long term. A dose about 5mg overrides the body's adrenals and will eventually atrophy them to stop working, so that you are reliant and at the mercy of cortisone tablets to stay alive for the rest of your life ... and need to understand how to manage your newly developed Addisons Disease and stress dose for sickness, surgery,broken legs etc. Its not a good medication but sometimes it is necessary and like all such things the good must outweigh the bad before a decision can be made.