Did you ever wonder how aromatherapy works, or why people choose this alternative treatment to help with a host of health conditions? Read on to learn more.

Aromatherapy is a spa treatment that uses plant-based essential oils for their health benefits. The oils of different plants produce different effects — lavender oil is used for relaxation, for example, while lemon oil is used to reduce stress. Certain oils are used to help fight bacteria, viruses, and fungi. More than 90 essential oils are used to help alleviate health conditions both physical and mental.

Aromatherapy works in two ways. First, scents influence the brain. Have you ever noticed how a smell can bring back a memory? This effect can be very powerful. Second, the oils themselves have properties that may trigger changes in your body. While most of the claimed effects of aromatherapy are still unproven, some studies have shown a benefit. In France, where aromatherapy was introduced, the oils are used regularly as medicine, and many are restricted and prescribed by a doctor. In the United States, essential oils are generally administered by an aromatherapist, or by a different type of therapist in conjunction with another treatment.

Essential oils can work on your body in various ways:

• Atmosphere. The oils scent the air you breathe and are often used in conjunction with another treatment, such as massage.
• Inhalation. When you directly inhale the aroma of oils, their therapeutic effects are delivered straight to your lungs. Essential oils that are commonly inhaled, like eucalyptus, help treat breathing problems, like congestion.
• Topical application. Oils are also applied to the skin, in compresses, during baths, and in massage. Because oils are too strong to be applied directly to the skin, they are diluted to 1 to 10 percent strength in another oil, often almond, apricot, or grapeseed oil. Because oils can be harmful in concentrations that exceed what experts generally recommend, most people prefer to see an aromatherapist rather than administering their own treatment.

You’ll see that a wide range of oils are used in aromatherapy. Popular choices include tea tree, lavender, catnip, rose, angelica, clove, cinnamon, sage, eucalyptus, bay leaf, cumin, thyme, juniper, lemongrass, sandalwood, peppermint, ginger, hyssop, rosemary, and lime.

Medicinal claims range widely as well. You’ll find that aromatherapy is used to:

• boost concentration, circulation, relaxation, and libido
• alleviate depression, headaches, stress, muscle aches, cold and flu symptoms, insomnia, nausea, menopausal symptoms, and inflammation
• help cure skin conditions and cold sores
• treat your specific problems, for which a therapist might blend two or more oils Skeptics claim there is little proof for aromatherapy’s benefits, because there haven’t been many conclusive controlled studies. Proponents argue that there is little financial incentive for studies because the oils can’t be patented.

Nonetheless, if you decide to give aromatherapy a try, keep in mind that the United States government does not regulate claims for aromatherapy, so you’ll need to find a practitioner you trust. If you’re concerned about the products a practitioner uses, ask to see product labels — make sure all ingredients are listed, and that fragrance oils are not included. Be wary of such packaging claims as “made with essential oils” — they don’t necessarily mean that a product is made 100 percent of essential oil.

In addition, essential oils can interact with some traditional Western medicines, so be sure to tell your doctor if you’re considering undergoing any aromatherapy treatments.