I never really examined aromatherapy, to be honest. I thought it had to do with the scents of natural oils and such - at least that's what was implied by marketing agents a couple decades ago who were intent on using the latest trend to sell products. (It is very "new age", you know) Turns out that it is the essence of the oils, themselves, that are reported to help heal, not the scents of the oils. Seems like aromatherapy could have used a marketing agent to better brand their product, huh?
Let's back up to the origins of this natural therapy. It's older than I thought it was. The name originated in the 1920s with a French chemist, René Maurice Gattefossé, but the application of oils for healing goes back to ancient times.
While vapors of these oils are sometimes prescribed, most times you rub them on your skin, massage them onto your body or ingest them in tea. There are quite a few books that will tell you which oils to use for which conditions. You can also find much of this information online - especially attached to stores which sell the oils.
It seems that most of the healing claims of essential oils have not actually been studied scientifically. Instead, people use personal stories of what worked for them or others and cite them as truth. For example, if I apply tea tree oil to a sore finger and a couple hours later it feels better, I might attribute the healing to the oil.
Early healers would use oils of all sorts which may or may not have helped their patients. It's really impossible to know very much with a lack of scientific studies of these substances. I suppose there is little harm in rubbing different oils on your body provided you don't have a skin reaction to them. I would be less inclined to ingest such things, however, unless you are positive they are non-toxic.
Personally, I prefer to seek treatments that my medical doctor prescribes as I believe they are more likely to be effective. I suppose a massage with a scented oil could be pleasant and I'm not going to say that it won't make you feel better. It's less likely to work for someone like me, however, as I don't believe it will, if you get my drift.
Such therapies will affect your pocketbook, I'm afraid. Essential oils do not come cheap! An online store sells lavender oil for $12.29 for 1/2 fluid oz. and tea tree oil for $8.32 per 1/2 fluid oz. At those prices, I'll stick to my scented candles.
Image found here