Usually when people go to visit a healthcare provider, they are feeling sick or something is wrong. In the world of Chinese medicine, people are encouraged to consult with a TCM doctor before something goes wrong so that they may be advised how to maintain their health, optimize their wellbeing, and prevent illness.
This is a lot easier to do if you are relatively healthy to begin with. Why wait till you are thirsty before digging a well? But most of us wait, often times to our detriment.
How does a TCM practitioner make a diagnosis?
If you were to visit a TCM practitioner with a specific complaint, the practitioner would assess your situation in its entire context.
First, a typical TCM practitioner will gather data. She will listen to your story, as well as gather information from "nonverbal elements," such as your demeanor, movement, voice, bodily sounds, and complexion. She will examine your tongue, take your pulse and temperature, and then feel your skin, muscle tone, internal organs, etc, as appropriate.
Your TCM provider is working under a set of diagnostic principles that strive to identify imbalance. This imbalance is made manifest by patterns of disharmony (known as bian zheng). An example of imbalance made manifest might be a headache.
The TCM provider would look at the headache in a large context, seeking to find if this disharmony is caused by excess (like too much stress or activity) or deficiency (like not enough food or sleep). For more information, see What Is Qi? (and Other Concepts).