Alternative medicine refers to healthcare practices, systems or products that are used instead of conventional medical treatment for a particular health problem. The word alternative indicates substitution rather than addition: if a person uses acupuncture instead of evidence-based treatment for an infection, for example, acupuncture is being used as alternative medicine, whereas using acupuncture alongside conventional treatment is generally described as complementary medicine. The term covers a highly heterogeneous collection of practices rather than a single coherent medical system.
Examples that may be described as alternative medicine include some forms of traditional medicine, homeopathy, naturopathy, certain herbal preparations, particular energy-based practices and various unproven diagnostic or therapeutic methods. Some practices classified as alternative in one healthcare system may be integrated into conventional care elsewhere, so terminology depends partly on historical, geographical and professional context.
Alternative medicine should be distinguished from complementary medicine, integrative medicine and conventional medicine. Complementary medicine is used alongside conventional care, while alternative medicine is used in its place. Integrative medicine generally describes an organised approach that combines conventional healthcare with selected complementary approaches in a coordinated, patient-centred manner, ideally using evidence about safety and effectiveness.
Conventional medicine refers broadly to healthcare based on established biomedical knowledge, clinical training, research evidence and regulated professional practice, although conventional medicine itself contains treatments with varying degrees of evidence. These terms therefore describe relationships between approaches as much as they describe particular therapies. The same intervention can move between categories depending on how and where it is used.
Alternative medical traditions have long historical roots. Systems such as Ayurveda, traditional Chinese medicine and various indigenous healing traditions developed over centuries or millennia, often incorporating extensive knowledge of plants, diet, physical practices, spiritual beliefs and observations of illness. Their historical longevity does not by itself establish that every component is effective for every condition, because traditional use and scientific evidence answer different questions.
Modern alternative-health markets also include practices developed much more recently, including products marketed using concepts that are not consistent with established physiology or pharmacology. It is therefore important to distinguish traditional knowledge, cultural healthcare practices, modern complementary therapies and unsupported commercial claims rather than treating all non-conventional approaches as one category.
Evidence for alternative medicine varies enormously. Some interventions commonly placed under the complementary or alternative umbrella have evidence supporting particular uses, while others have limited, inconsistent or no convincing evidence for claimed effects. Evidence must be evaluated for the specific intervention, dose, preparation, indication and outcome rather than assuming that an entire medical tradition is either effective or ineffective.
Randomised controlled trials can help determine whether an intervention produces effects beyond placebo and other influences, while systematic reviews and meta-analyses assess evidence across studies. Observational evidence can identify associations and possible safety signals but is more vulnerable to confounding. A treatment can also be biologically plausible without having demonstrated clinical effectiveness, so plausibility and evidence of benefit should not be treated as equivalent.
A major concern with alternative medicine is the possibility of replacing effective treatment with an intervention whose benefits are uncertain or absent. This can be particularly dangerous for conditions in which early treatment is important, including serious infections, cancer, heart attack, stroke and severe mental-health conditions. Delayed diagnosis can also be harmful because symptoms attributed to a benign condition may actually represent a serious disease.
The risk is not limited to treatment failure: some herbal products can cause toxicity or interact with medicines, some procedures can cause physical injury, and contaminated or adulterated products can introduce additional hazards. The safety of a practice therefore needs to be considered independently from whether its claimed therapeutic effect has been demonstrated.
The placebo effect is relevant to discussions of alternative medicine but does not mean that symptoms experienced by patients are imaginary. Expectations, conditioning, therapeutic attention, changes in behaviour and natural fluctuations in symptoms can all influence perceived outcomes. In controlled trials, a treatment's effectiveness is normally assessed by comparing it with an appropriate control so that these influences can be separated as far as possible from treatment-specific effects.
Some interventions may improve subjective outcomes such as pain or nausea without demonstrating effects on underlying disease progression. Consequently, a person reporting improvement after an alternative treatment provides useful information about their experience but does not by itself establish that the treatment caused the improvement or that it will work reliably for other people.
Regulation differs substantially between countries and between types of products or practitioners. A product being legally available does not necessarily mean that its effectiveness for a particular disease has been established to the same standard required for a licensed medicine. Herbal and nutritional products can have pharmacologically active constituents, variable concentrations and interactions with prescription medicines. Manufacturing quality, contamination, incorrect labelling and batch variation can also be relevant.
Consumers should be particularly cautious about claims that a product can treat many unrelated diseases, replace conventional treatment, detoxify the body, cure serious conditions without evidence or work because it is described as natural. Natural is not synonymous with safe, and conventional is not synonymous with effective in every individual case.
The most useful modern approach is to assess alternative practices individually according to evidence, safety, plausibility, quality control and the consequences of delaying proven care. A person considering such an approach should tell their healthcare professionals about relevant therapies and products because interactions and duplication of treatment can matter. Alternative medicine is therefore best understood as a broad descriptive category rather than a scientific classification of treatments. Its defining feature is substitution for conventional care, but the scientific status of individual practices ranges from well-supported uses to uncertain, disproven or potentially hazardous claims.
