The basic premise behind the medicine is that humans are dependant on energy to live and be healthy. In the East this energy of the body is called 'Qi' and is said to 'flow' through our bodies giving us life. We can probably best understand this by thinking how difficult it is to think and function well when we are tired or exhausted, we say we have 'no energy'. It is at these times we get upset, run down or ill. On the other hand when we are full of energy life seems easier, we do not get so run down and can throw off or escape that 'flu or whatever illness it is going round.
Acupuncture works by improving the body's energy.
When the energy of the body does not flow well we may get problems such as migraine and pain. The treatment of pain using acupuncture is well documented as to it's efficacy. The Chinese were very observant people. In the China of two or three thousand years ago the doctors had no machines to do tests, or even have a detailed theory of the workings of the body as we understand it in the West today. These techniques were not peculiar to China - virtually every tradition in the world used these methods to diagnose illness.