Some patients who are given a sugar pill to treat headaches feel much better. this is an example of the:

This is an example of a placebo effect. A placebo is something that seems to be a "real" medical treatment but the truth, it isn't. It could be a pill, an injection, or some other kind of "fake" treatment. What all placebos have in common is that they do not encompass an active substance meant to affect health.