This article is from the Alternative Medicine Therapies guide.
A considerable body of research shows that smell, the most acute of our senses, has a powerful influence on our bodies and minds. The scents from essential oils are believed to activate olfactory nerve cells in the nasal cavity, which then send impulses to the limbic system, the area of the brain associated with emotions and memory.
Proponents of aromatherapy believe that the aromatic oils work both emotionally and physically. Emotionally, they may make you feel better by evoking a pleasant memory (the smell of lemons might remind you of a cake a favorite aunt once made, for example). Physically, they may help to relieve certain conditions by stimulating the immune, circulatory, or nervous systems.
Aromatherapists stress that only pure, natural, unadulterated essential oils have true medicinal properties. Perfumes, shampoos, and bath oils scented with herbs may smell wonderful, but they are not intended to be therapeutic.