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Overview of Complementary and Alternative Medicine

By Steven Rosenzweig, MD, Clinical Associate Professor, Drexel University College of Medicine

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Complementary and alternative medicine (CAM) includes a variety of healing approaches and therapies that are taken from around the world and that historically have not been included in conventional Western medicine. Many aspects of CAM are rooted in ancient, indigenous systems of healing, such as those of China, India, Tibet, Africa, and the Americas. Many of these treatments and health care practices are popular, and now some are used in hospitals and are reimbursed by insurance companies. Acupuncture and some chiropractic treatments are examples. Because interest in and use of CAM are increasing, more and more medical schools are including information about CAM treatments, such as acupuncture, herbal medicine, chiropractic treatments, and homeopathy.

  • Complementary medicine: CAM practices are used with conventional medicine.

  • Alternative medicine: CAM is used alone.

Integrative medicine refers to the use of all appropriate therapeutic approaches (conventional and alternative) in a framework that focuses on the whole person and that reaffirms the relationship between doctor and patient.

Although the distinction between conventional medicine and alternative medicine is not always easy to determine, a basic philosophical difference exists. Conventional medicine generally defines health as the absence of disease or dysfunction. The main causes of disease and dysfunction are usually considered to be isolated factors, such as bacteria or viruses, biochemical imbalances, and aging, and treatment often involves drugs or surgery. In contrast, alternative medicine practices often define health holistically, that is, as a balance of systems—physical, emotional, and spiritual—involving the whole person. Disharmony among these systems is thought to cause illness. Treatment involves strengthening the body’s own defenses and restoring these balances.

Did You Know...

  • Americans now make more visits to alternative medicine practitioners than to primary care doctors.

Acceptance and Use

An increasing number of people in Western countries are exploring alternative medicine as part of their medical care. In 1997, Americans made more than 629 million visits to alternative medicine practitionersa 47% increase since 1990. This number substantially exceeds the 386 million visits made to all primary care doctors in the same year. In 2007, 38% of Americans 18 years of age or older used some form of alternative medicine. The conditions for which people are most likely to seek alternative medicine treatments include the following:

  • Musculoskeletal problems (for example, chronic lower back pain, neck pain, or joint pain)

  • Anxiety

  • High blood cholesterol levels

  • Head or chest colds

  • Headaches

  • Sleep problems

Additionally, many people facing life-challenging illnesses, such as cancer, seek alternative therapies when conventional treatment offers little hope, especially at the end of life.

Effectiveness and Safety

In 1992, the Office of Alternative Medicine within the National Institutes of Health (NIH) was formed to research the effectiveness and safety of alternative therapies. In 1999, this office became the National Center for Complementary and Alternative Medicine (NCCAM—visit their website at


The effectiveness of alternative therapies is an important consideration. Some therapies have been shown to be effective for specific conditions, although these therapies are applied more broadly. Many forms of alternative medicine have not undergone rigorous scientific evaluation. However, a lack of scientific studies does not mean that a therapy is ineffective. A large number of alternative therapies have been practiced for thousands of years. They include acupuncture, meditation, yoga, therapeutic diets, massage, and herbal medicine. However, it can be difficult to do scientific research studies on them. Barriers to doing research on CAM therapies include the following:

  • Lack of interest among medical researchers

  • Limited availability of research funds

  • Difficulties applying conventional research methods to studying alternative therapies

An example is acupuncture. Medical researchers often have little scientific interest in acupuncture because its theory depends on nonscientific notions such as vital energy. Commercial research funds are limited because acupuncture cannot be patented. Thus, there is no profit motive. Government research funds are limited because the scientific community remains skeptical of acupuncture theory and the validity of its method.

Applying conventional research methods to study CAM is difficult for many reasons, including

  • Conventional research design requires that the same treatment be given to every person in the study (subject). However, many CAM therapies treat the unique and particular imbalances of individual people. For example, acupuncture needles are placed at points on the body according to a person’s unique needs, or people with the same medical diagnosis may be prescribed completely different homeopathic or herbal medicines.

  • Conventional research design compares active treatment with a placebo (an intervention that is made to resemble a drug or treatment but does not include an active drug or treatment—see see Placebos). Some CAM therapies, such as homeopathy and herbal medicine, lend themselves to placebo design. However, designing a placebo acupuncture or chiropractic treatment is difficult. Designing a placebo for meditation is impossible.

  • Conventional research design uses the method of double blinding (preventing research subjects and researchers who work directly with them from knowing which people are receiving a new treatment—see see The Science of Medicine). Double blinding reduces the bias of people who receive an active treatment expecting or being expected to do better than the control group. Placebos are used to blind subjects, but placebo design may be limited in CAM. Researcher blinding may also be limited. For example, a Reiki practitioner would know whether a real energy treatment is being given.

If an alternative therapy has been proved ineffective, its use cannot be further advocated scientifically.


Safety is another important consideration. Although some CAM therapies can have risky side effects, the greatest risk occurs when a person is treated with an unproven CAM therapy instead of a proven conventional medicine approach. Regarding the risk of CAM therapies themselves, some are clearly safe. Examples are using meditation for pain management, acupuncture to treat nausea, yoga to improve balance, or ginger tea to aid digestion. Others may conceivably be harmful. Because herbal medicines and other dietary supplements (which are used in many alternative therapies) are not regulated as drugs by the Food and Drug Administration (FDA), their manufacturers do not have to prove their safety (see Overview of Medicinal Herbs and Nutraceuticals : Safety and Effectiveness).

Some general risks include the following:

  • Some substances may interact dangerously with prescription drugs.

  • Although highly purified dietary supplements are readily available in the United States and many countries in Europe, products produced in other countries may contain dangerous contaminants, toxic ingredients, or other drugs.

  • Harm can be done by alternative therapies that involve manipulation of the body or other nonchemical interventions (for example, manipulation that injures vulnerable parts of the body).

In many cases of alternative medicine, harm has neither been established nor excluded, but in some cases, potential harm has been shown. Sometimes the potential for harm is widely discounted by people who advocate use of the alternative product or therapy.

Types of Alternative Medicine

Alternative medicine can be classified into five major categories of practice: whole medical systems, mind-body techniques, biologically based therapies, manipulative and body-based therapies, and energy therapies. The category names only partially describe their components. Some approaches are understandable within the concepts of modern science, whereas other approaches are not. Many types overlap with others.

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