The actions of the essences then vary according to their constituents. Some stimulate our circulation, increasing the rate of elimination of toxic substances such as uric acid. Other oils act on specific organs, increasing their secretions of body chemicals such as the production of bile by the liver, or oestrogen by the ovaries. The majority are highly antiseptic, and thus extremely useful in the treatment of infections. Many essences also have an analgesic effect, and the aromatherapy treatment can stimulate the release of endorphins - body chemicals which have a painkilling and antidepressant effect.
Most essential oils have a specific effect on the emotional as well as the physical level.
As the vapours are inhaled impulses pass along the olfactory nerve from the nasal cavity, which is connected to the limbic system in the brain. This is the part of the brain that deals with memory and emotion. Certain oils then stimulate specific neuro-chemicals within the nervous system Sedative oils such as lavender and marjoram stimulate the neurochemical serotonin, which induces sleep. These oils therefore have a calming, sedating effect and can, for instance, be used to treat tension and insomnia. Holistic aromatherapy, by restoring and promoting the balance between body and mind, can help prevent illness.