So what is aromatherapy anyway? Well, the name pretty much says it all—it's the practice of using aroma, or smell, as therapy to treat the entire person (not just the symptom or disease). Though the term aromatherapie only evolved in the early 1900s, the practice of scenting air and body with natural plant extracts for medicinal purposes dates back to ancient China, India and the Middle East. According to the National Association for Holistic Aromatherapy , "Aromatherapy can be defined as the art and science of utilizing naturally extracted aromatic essences from plants to balance, harmonize and promote the health of body, mind and spirit."
Basically, while each individual might have a unique physical, emotional or spiritual response to a certain scent, there are a set variety of plant essences that have been seen to effect particular states of mind. These scents can be used either as preventative or active therapy by balancing and regulating the body's processes—thereby promoting the natural healing innate to an individual.
The essential oils used in aromatherapy are extracted from plants, grasses, fruit peels, wood, roots and leaves. The manufacturers use water and steam or expression (cold pressing) that gathers only the most potent elements of the organic materials, giving you all the benefits in the convenience of a tiny glass bottle that goes a very long way.
Aromatherapy is often a hands-on practice, as it can be used in massage or at pressure points around the body to complement the practice of acupuncture (which I'm going to cover next) and other body treatments. However, it can also be used simply as an environmental stimulant, giving scent to the air and allowing the oils to take effect simply through your sense of smell. Using single scents or scent combinations—you can buy pre-mixed essential oil combinations—will affect the result of the aromatherapy, and the art of mixing different scents (five is the max generally recommended) to achieve combined results is something that takes years to perfect. But as long as you're not drinking them or putting them on your skin, there's no harm in experimenting!