We have probably all heard of this one. Belief is powerful medicine, even if the treatment itself is a sham. The placebo effect is the measurable, observable, or felt improvement in health not attributable to an actual treatment. An inert substance, such as a sugar pill, pure water or saline, is substituted for an effective medical treatment without the knowledge of the patient. The substance has no real medical value; however a patient may still improve merely because their expectation to do so is so strong.