Sometimes cortisone shots can alleviate pain for up to six weeks. The cortisone can be like a miracle drug, it's a combination of a steroid and local anesthetic. Although, it can feel like a miracle it certainly is not fixing the problems beneath the pain. You can think of the cortisone as a "quick-fix" and when has anything that's a "quick-fix" been good for you (liposuction, fad diets, etc...)? I usually suggest fixing the underlying problem, that means visiting the surgeon, the physical therapist or the podiatrist to get advice on fixing what's causing the pain.
The pros of the cortisone shots can be an immediate decrease in joint inflammation and pain. Like every medical treatment, cortisone shots do come with potential side effects that can include more inflammation, nerve damage, bone damage and a weakening of tendons in the joint. Most physicians will limit the number of cortisone shots due to fear of additional damage in the joint.
My advice: If you are in an enormous amount of joint pain, the cortisone can certainly be beneficial, but find the time for a proper evaluation to locate the origin of the pain so it can properly be rehabbed by a professional. (And while we are at it, let's get rid of the "quick-fix" fad diets.)