If this is the first time you have a nail infection, you will need to visit a hospital where your doctor will confirm the diagnosis of nail fungus and then treat it under your doctor’s guidance. As the nail plate grows slowly, especially in older people whose toenails grow more slowly, topical medication needs to be adhered to until the diseased nail grows out completely, a process that often takes at least six months. If the nail fungus is severe, oral antifungal medication may be required, at which point it is even more important to be guided by a doctor and tested for adverse drug reactions.