The term medicine refers to a substance that can be used to treat or prevent a disease or illness. It can also refer to that art or science used to cure a disease. There are two type of medicine, conventional and alternative. Conventional medicine can be said to be the modern medicine commonly used, and mostly act from the inside of our bodies. Such medicine will include drugs and further on, surgery (an art). Alternative medicine can be said to be any other form of art or science used to treat disease. This has a long history than conventional medicine, as most of the alternative medicine available dates back thousands of years, having been used by our forefathers. Alternative medicine does not involve any surgery.

The term Complimentary and Alternative Medicine (CAM) is presently common. Complimentary and Alternative are used interchangeably but both refer to Alternative Medicine. Complimentary is used to show that alternative medicine compliments conventional medicine.

The use of alternative medicine has been controversial in many countries. While a certain type of medicine may be considered as alternative in one country, the same can be viewed as conventional in another. Arguments also persist between those who practise conventional medicine and those who prefer alternative medicine, with the former arguing that the latter is ineffective.

Despite such arguments and disagreements, the use of alternative medicine has continued to grow. Alternative Medicine Institutes such as NCCAM have been established in many countries to undertake studies and development of alternative medicine. Colleges and universities across the world have established full faculties dedicated to the study of alternative medicine with professionals in the same field.

A survey done by American National Centre for Health Statistics (CDC) and NCCAM in 2002 showed that 74.6% people used CAM 54.9% people used CAM with conventional medicine, 14.8% had sought CAM treatment from licensed practitioners (suggesting that most of those surveyed went for self treatment). The study indicated that most of those who used CAM did so for chronic, recurring conditions and musculoskeletal conditions. The survey also indicated that women used CAM more than men, their main therapy being mind and body. Among CAM therapies, the survey revealed that prayer accounted for the largest percentage (45.2%), followed by herbals (18.9%), meditation (11.6%), chiropractic (7.5%), yoga (5.1%), diet-based therapy (3.5%), relaxation (3.0%), mega-vitamin therapy (2.8%) and visualization (2.1%).

The use of CAM is growing at a rapid rate and while those in the developed countries can be said to practise 'modern' alternative medicine, those in developing countries, particularly Africa, can be said to use the traditional. These include mostly herbs where plant leaves, stems and roots are sourced, boiled and used. Some plant parts are burnt into ash and either consumed or used externally.

The National Center for Complementary and Alternative Medicine (NCCAM), which is part of American National Institutes of Health has classified alternative medicine into five major groups. The classification is mainly based on the medicine's mode of action.

(a) Traditional Chinese Medicine.

(b) Homeopathy

(c) Naturopaethic Medicine

(d) Acupuncture

(e) Ayurveda