First, it is prudent to have a working definition of conventional or mainstream healthcare. Conventional (a.k.a. mainstream) medicine is that which is practiced by licensed MDs (medical doctor) and DOs (doctor of osteopathy) and their associated practitioners (phamacists, registered nurses, and more). ONLY licensed medical practitioners may legally diagnose, treat, or prescribe.
Alternative healthcare encompasses those modalities of healing outside the conventional / mainstream system. So, seeing a chiropractor instead of a MD for back pain is a form of alternative healthcare; some other modality is used in place of the mainstream method.
Complementary healthcare includes those things which fall into the alternative definition but are use along side conventional / mainstream healthcare. So, diffusing Eucalyptus radiata in the home during a sinus infection while taking an antibiotic for the sinus infection as prescribed by an MD is complementary.
This line is not always as clear as the examples above, so, Complementary and Alternative Medicine (CAM) is the term used to describe the use of these modalities either in place of or alongside mainstream medicine.
Aromatherapy is a CAM modality. An aromatherapist may not diagnose, treat, nor prescribe, however, they may educate and empower people with regard to wellness using essential oils.
