Acupuncture is all about movement of energy in the body - improving the balance of the energies which underlies normal functioning.
What does this mean? What energies?
The Chinese and many other Eastern cultures have always seen the body and mind as one entity, and one that functions first at the level of energy, and only secondarily at the level of matter: flesh and bone. Where the balance and flow of energy is correct, the functioning of the organs and body systems is correct, and the person feels healthy, and at ease. The balance of energies may become disturbed for many reasons. To be healthy and happy we need neither too much nor too little of many things; activity, exercise, rest, sleep, stimulating challenges, rewarding relationships, good food and drink and so on. Some of these we have control over, some we may not. We also carry the effects of past experience, physical and emotional. In addition we have constitutional weaknesses and strengths which may or may not play a large part in our lives.
So what can acupuncture do about this?
The flow of energy is accessible near the surface of the body at points which lie along the meridians - symmetrically placed channels on each side of the body and running along the centre line. The balance of energies can be changed by acting on these points - traditionally, by needling them. Fortunately for those who hate needles, they can also be changed using a soft laser, or by stimulating the points electrically, or by techniques using simple pressure.
Does Western medicine go along with this?
Largely, yes. Western medicine has no similar concept of energy and its flow in the body, so tends to ignore this, since it can't be measured. There is, though, plenty of Western research showing that acupuncture is effective, and brings about hormonal changes, and changes in nerve function, which can be measured.
So you put a few needles in and people are cured?
I wish! A good treatment shifts the balance of energies to give improved functioning. If the causes of the disease are not addressed at the same time, this improvement will be only temporary. If the disease state is very profound, it may take a number of treatments to affect it at all. However, the body is trying to heal itself all the time, and usually makes surprisingly good use of any help it is given. Acupuncture is one of the most powerful healing techniques I know of.