Chinese medicine
In Chinese medical theory, health is maintained through an intricate system of balance, one that depends on both the internal and external worlds complimenting each other.
I think the NYC subway system is a good analogy for the workings of Chinese Medicine. The city is transversed with pathways that have stops all along them, just as our bodies are transversed with channels that have acupuncture points all along them. In the subway system and in our body some of these lines cross and interact with each other directly, while some require a third pathway to cover the distance between them.
A problem anywhere in our body is similar to a problem anywhere in the transit system – nothing is isolated. For example, if there is a track fire at 34th street, it's going to affect the stops all along that line, as well as any lines that cross it. Other trains will have to slow down, change their route, and hold more passengers until the malfunctioning line is cleared. Even if you are standing at a station well below 34th street, where the tracks look just fine, you know there's a problem because the platform is overcrowded and the trains are not coming. To translate this into Chinese medical theory: the rest of the line is obstructed from free, smooth functioning, and the longer the blockage is allowed to remain, the larger the area of congestion becomes.
What happens if that malfunction is never dealt with? Eventually, the whole system will become ravaged by areas of overcrowding, areas of emptiness (no service) and a general lack of progress.
This is what is happening inside your body at the onset of disease. What may begin as a small isolated problem (an injury or the beginning of an illness), if left untreated, will eventually affect other areas on the same channel and then spread to additional channels.
Fatigue, colds, poor digestion and injuries are opportunities for us to right a disease process before it affects the whole system. By needling into acupuncture points (the subway stations), obstructions can be cleared and weakness can be strengthened, until the channel is able to interact again with the entire system in a healthy manner.