Aromatherapy, or essential oils therapy, is using a plant's aroma-producing oils (essential oils) to treat disease. Essential oils are taken from a plant's flowers, leaves, stalks, bark, rind, or roots. The oils are mixed with another substance (such as oil, alcohol, or lotion) and then put on the skin, sprayed in the air, or inhaled. The oils can also be massaged into the skin or poured into bath water. Aromatherapy originated in Europe and has been practiced there since the 1920s.

Practitioners of aromatherapy believe that fragrances in the oils stimulate nerves in the nose. Impulses are then sent to the part of the brain that controls memory and emotion. Depending on the type of oil, the result on the body may be calming or stimulating.