Qi, Yin and Yang, Five Phases and Meridians as Traditional Concepts

Why these are called traditional concepts

Traditional Chinese medicine describes the body and illness with its own vocabulary. A nursing journal introduction to the theory behind acupuncture lists the concepts as imbalances of ch'i (qi), or vital energy, yin and yang, meridians, vital substances, pathogenic factors, five phases and eight principle patterns. [1] These ideas come from a long written tradition, including classical works such as the Huangdi Neijing (Yellow Emperor's Inner Classic). [2] They are best read as the tradition's own explanations. They are not biomedical mechanisms, and this page does not present them as such.

Four kinds of statement are kept apart across this site: a traditional explanation (what the tradition says), a proposed mechanism (a hypothesis about how something might work), a physiological finding (something measured in the body) and a clinical outcome (whether people feel or function better in a trial). See Traditional Frameworks vs Biomedical Explanations.

Qi

In the tradition, qi is described as a vital energy, and illness is described as an imbalance of it. [1] NCCIH describes qigong as using exercises to optimize energy within the body, mind and spirit. [3] "Energy" here is a traditional term; it is not a form of energy that biomedicine measures. Proper evidence not found for a measurable biomedical equivalent of qi in the sources we checked (NCCIH, PubMed reviews on points and meridians).

Yin and yang

Yin and yang are one of the traditional theories the tradition uses to explain health and imbalance. [1] They are not a lab test. Nothing in the sources we read tests yin and yang as biological measurements.

Five phases

The five phases (sometimes called five elements) are another traditional framework listed alongside yin and yang. [1] Proper evidence not found for clinical trials that test the five-phase framework itself as opposed to specific treatments.

Meridians as a traditional framework

Meridians are another of the traditional concepts listed in this framework. [1] Within the acupuncture community there is a view that points and meridians are special conduits for electrical signals, and researchers have looked for physical signs. [4] A systematic review of 16 articles (18 studies) on electrical properties found some studies reported lower electrical resistance at points and along meridians, but the studies were generally poor in quality, small and prone to confounding, and the review concluded the evidence does not conclusively support the claim that points or meridians are electrically distinguishable. [4] A Chinese-language review of research on the structure of acupuncture points described studies of skin, nerves, vessels and cells, and said understanding still lags behind what is needed. [5]

Label: meridians as physical structures: insufficient evidence. This does not decide whether acupuncture helps a given problem, which is tested by trials: see What Is Acupuncture?.

How this fits with practice

Practitioners use these concepts to explain a person's situation and plan treatment. Their use in assessment is covered in Traditional Pattern Differentiation. Whether a treatment helps does not depend on whether you accept the theory, and a treatment can be traditional and still unproven, or traditional and supported by good trials. Each practice is judged on its own evidence: TCM Evidence by Use.

Safety note

You do not need to accept any framework to be safe. Do not delay care for new, severe or worsening symptoms because a traditional explanation sounds reassuring. NCCIH advises not using TCM to replace or delay conventional care. [6]