Reflexology is an alternative medicine involving application of pressure to the feet and hands with specific thumb, finger, and hand techniques without the use of oil or lotion. It is based on a system of zones and reflex areas that reflect an image of the body on the feet and hands, with the premise that such work affects a physical change to the body.
A 2009 systematic review of randomised controlled trials concludes: "The best evidence available to date does not demonstrate convincingly that reflexology is an effective treatment for any medical condition.
There is no consensus among reflexologists on how reflexology is supposed to work; a unifying theme is the idea that areas on the foot correspond to areas of the body, and that by manipulating these one can improve health through one's qi. Reflexologists divide the body into ten equal vertical zones, five on the right and five on the left. Concerns have been raised by medical professionals that treating potentially serious illnesses with reflexology, which has no proven efficacy, could delay the seeking of appropriate medical treatment.