Aromatherapy is a form of alternative medicine that uses volatile plant materials, known as essential oils, and other aromatic compounds for the purpose of altering a person's mood, cognitive function or health. The effectiveness of aromatherapy is yet to be scientifically proven, however some evidence exists that essential oils may have therapeutic potential.

Since some essential oils such as tea tree have demonstrated anti-microbial effects, it has been suggested that they may be useful for the treatment of infectious diseases. The evidence base for the efficacy of aromatherapy used to treat medical conditions remains poor with a particular paucity of methodologically rigorous studies

Aromatherapy may have origins in antiquity with the use of infused aromatic oils, made by macerating dried plant material in fatty oil, heating and then filtering. Many such oils are described by Dioscorides, along with beliefs of the time regarding their healing properties, in his De Materia Medica, written in the first century.Distilled essential oils have been employed as medicines since the invention of distillation in the eleventh century,when Avicenna isolated essential oils using steam distillation.

The concept of aromatherapy was first mooted by a small number of European scientists and doctors, in about 1907. In 1937, the word first appeared in print in a French book on the subject: Aromathérapie: Les Huiles Essentielles, Hormones Végétales by René-Maurice Gattefossé, a chemist. An English version was published in 1993.In 1910, Gattefossé burned a hand very badly in a laboratory explosion. The hand developed gas gangrene, which he successfully, and intentionally, treated with lavender oil[citation needed].

A French surgeon, Jean Valnet, pioneered the medicinal uses of essential oils, which he used as antiseptics in the treatment of wounded soldiers during World War II

.