Ever seen that drawing of two silhouettes looking at each other? One moment you see two faces, the next moment, its a vase. Which is it? Obviously it is just a matter of your perception or the way your brain links together visual clues.
That's the difference between Western medicine, and Chinese or Oriental medicine. Diagnosing the same patient with a lump in her breast, the Western Doctor will see a cyst, lesion, fibroid or cancer whereas the Chinese Medical doctor will see a stagnation of Qi, Blood, or Phlegm. The Western Doctor will seek to prove the diagnosis with a biopsy of the hardened tissue. The practitioner of Chinese medicine will feel the unique quality of the pulse at the radial artery which may feel "wiry" or kind of hard, like a guitar string bouncing up and down beneath your fingers (as opposed to other pulses that can feel softer and more flowing), observe the color and shape of the tongue looking for purple in particular, with possibly a thick yellow coating. Also used for diagnostic purposes will be seemingly unrelated symptoms such as a sensation of constriction in the chest, abdominal bloating, heightened emotional sensitivity and a tendency to be easily angered, and frequent headaches at the top or the sides of the head. This will allow the doctor of Chinese medicine to come up with a diagnosis of "Qi, Blood or Phlegm stagnation." Same symptoms, same signs, same patient, but very different ways of organizing the information.

　　　Within each discipline, there is an enormous amount of time tested information that has its own logic and usefulness. Both Western and Chinese systems have their place. Some believe that the greatest strength of Western Medicine is in it's trauma care and therapies for acute problems, while Chinese medicine excels in the areas of chronic problems and preventive medicine.

　　　One concept that is central to Chinese medicine that the scientific world is still struggling to accept is an internal substance that the Chinese call "Qi" (pronounced "chee", sometimes spelled "Chi"). In the West we could describe this as bio-electric energy. You can't look at it under a microscope, you can't detect it with any scientific instruments, you can't isolate it from a substrate. This isn't to say that one cannot feel it, or see it, but these are intuitive human qualities that practitioners of Chinese medicine develop over years of practice. Many westerners can also perceive this Qi energy. Martial artists sometimes feel it as heat in the palms of their hands, or warm liquid moving through the body. It is the invisible substance in mountain air that clears the mind with just one deep breath. A young mother witnesses it in the form of light coming from her baby's eyes.
Acupuncture seeks to treat health on the level of Qi. There are pathways in the human body wherein this Qi flows. They are called meridians, or channels. Needles inserted along these meridians influence the Qi that flows to internal organs. It can affect both the structure and function of these organs. Needles can also work on specific areas of pain that may not be associated with internal problems, sport injuries, for example. A needle inserted near the area of a pulled tendon or overstrained muscle will increase the flow of Qi to that area which removes pain and quickens the healing process.
Another aspect of the difference between Oriental and Western medicine can be described as Oriental treats the Yang and Western treats the Yin.
　　　Everything in the universe can be described in terms of Yin or Yang. This is one of the underlying philosophies of Oriental Medicine. The Chinese characters for Yin and Yang mean, literally, the sunny side of the hill and the shady side of the hill.