NCCAM classifies natural, complementary and alternative medicines into 5 categories, or domains
1 Alternative medical systems	Alternative medical systems are built upon complete systems of theory and practice such as homeopathic and naturopathic medicine, Traditional Chinese medicine and Ayurveda.
2 Mind–body interventions	These interventions include counselling, patient support groups, meditation, prayer, spiritual healing, and therapies that use creative outlets such as art, music, or dance.
3 Biologically based therapies	These therapies include the use of herbs, foods, vitamins, minerals, dietary supplements.
4 Manipulative and body-based methods	These methods include chiropractic or osteopathic manipulation, and massage.
5 Energy therapies	Energy therapies involve the use of energy fields. They are of 2 types: 1. biofield therapies such as qigong, reiki, therapeutic touch 2. bioenergetic therapies involving the use of pulsed electromagnetic fields, such as pulsed fields, magnetic fields, or alternating-current fields and/or alternating- and direct-current fields.

As the evidence-base for some CAM increases, medical practitioners have a legal obligation to inform patients of the efficacy of relevant complementary therapies as treatment options, and to simultaneously be aware of the potential for adverse events and interactions that CAMs, such as nutritional and herbal supplements, may have when co-administered with pharmaceutical drugs or when a patient denies good orthodox care for any unproven CAM.¹¹ Knowledge in the efficacy of a complementary medicine or therapy is essential when making clinical decisions for patient care to help weigh against potential risks, such as adverse reactions or delays in useful conventional treatment. This highlights the importance of medical practitioners having at least basic education in the area of CAM to enable them to communicate and inform patients about what therapies are appropriate to the individual. Education on potential risks such as nutrient toxicity, especially with single nutrient use, and any potential interactions with pharmaceuticals is also essential.

Popularity of IM and CAM

Worldwide reports demonstrate that a large proportion of the public are using CAM and its popularity is increasing. For example, in Australia up to 70% of the population are using CAM.¹² In the United States, up to 62% of adults use CAM.¹³ It is therefore vital that health and medical practitioners are well informed about the evidence in these areas.

In many respects, the enthusiasm to use CAM is largely driven by the public. The community has greater access to information and various complementary medicine practitioners and therapies. There are often various reasons why a patient will want to trial CAM. These include philosophical and cultural reasons — wanting a more holistic approach to health care, when there are no longer any other orthodox approaches to assist in their health care, especially if they have suffered any adverse events from orthodox treatments. Generally, patients who use CAM are not rejecting orthodox medicine but are looking for options to improve wellbeing. Unfortunately, medical practitioners underestimate the extent of use of CAM by patients.^14,¹⁵ This is of great concern, considering the potential for adverse events such as herb–drug interactions and coordinating the overall management of the patient.

Cultural aspects in determining type of CAM use

The WHO estimates that approximately 60% of medicine that is practiced worldwide is traditional medicine.¹⁶ Traditional Chinese medicine (TCM) is practised in many Asian countries, Ayurveda medicine in India, Unani medicine in the Middle-East, Pakistan and India, while Kampo medicine is used in Japan. Biomedicine or conventional medicine is the predominant medicine practised in developed countries and its formation has also been influenced by cultural factors.¹⁷

Many of these therapies have been used for centuries, and some for thousands of years, and have a long traditional use in some societies and cultures, being highly entrenched in their health care system. There may be little scientific evidence for these therapies, but some inherent safety considering long-term use, in some cases up to 2000 years.

Although it is correct to offer patients conventional medical treatment for acute illnesses, for a chronic illness though for which there is no ‘right’ answer it is likely that the best treatment is that which best matches the patient’s belief systems and cultural understanding. For example, a patient of Asian background may be very keen to use either herbal medicine or acupuncture. Under these circumstances it is mandatory that the practitioner is aware of possible toxicity, interactions with conventional medicines and the cost of such therapy.