Compared to Western Medicine, TCM is quiet different and unique. In general the modern western medicine looks closely at a symptom and focuses on a specific cause for each disease. When the cause is found, it tries to either control or destroy it. The traditional Chinese medicine on the other hand takes a different approach. TCM looks and treats the human body as whole and considers the each organ to have a mental as well as a physical function. Considering the physiological and psychological aspects of the patient, it traces the root cause of all diseases and then treats the patient by correcting the critical imbalance in the patients energy system that has cause the disease in the first place.

Yin and Yang
The underlying and the fundamental concept of TCM is that of natural balance which is based on the principles and theory of yin yang and five elements. The twin philosophies of Yin and Yang is a cosmic dualistic approach where two opposing forces flow into one another and constantly interacts to create all things and all development. Yin represents the negative or passive female principle. Yang represents the positive or active male principle. All things have a yin viewpoint and a yang viewpoint. Below is an excerpt from the Huang-Di Nei Jing, or "The Yellow Emperor's Canon of Internal Medicine," which illustrates the relationship of yin and yang:

Yang has its root in Yin
Yin has its root in Yang.
Without Yin, Yang cannot arise.
Without Yang, Yin cannot be born.
Yin alone cannot arise; Yang alone cannot grow.
Yin and Yang are divisible but inseparable.

In Chinese medicine health is represented as a balance and harmony of yin and yang while disharmony leads to bad health. However it is important to point out that the balance of yin and yang is not always same or exact. In general the change in the balance of yin and yang is very natural and may happened due to mental or psychological conditions. For example, a person's mood may be more fiery, or yang, whilst at other times he may be quieter and therefore more yin. If however, the balance is permanently disordered, and one regularly dominates or consistently outweighs the other, then the body is unhealthy and disease results.

Three Treasures - Vital Substances
According to traditional Chinese medicine, the human body is an energy system, made up of different fundamental substances and functions. They are the three treasures (San Bao) known Shen, Jing and Qi as well as blood and body fluids.
Body Fluid (Jin Ye) or moisture is formed from food and drink. It is the liquid medium, which protects, nurtures, and lubricates tissue. Blood is a plasma-based fluid that nourishes the body and spirit. Blood is the material foundation for bone, nerve, skin, muscle, and organ creation.
Qi(Chi) can be loosely translated as vital energy or life force that exist in all of us and gives us our capacity to move, think, feel and work. Qi is build from the food we eat and the air we breathe. Qi is a very wide concept, an essential part of the human body and the basis of all life. Together with moister and blood it in channels called the meridians keeping us very much alive and healthy.
Shen is the spirit, immaterial expression or in other words the mental and spiritual side of an individual which controls the jing and qi. Jing is the essence, the fundamental substance that forms and maintains life. Jing regulates growth, development, reproduction, and promotes and works with chi to help protect the body from external factors. The three treasures form one whole unity. If any of the three are weak, there will be illness, and if any disappears completely, there will be death.

Zang-Fu
Zang and Fu are the terms used to describe various internally visible yin and yang organs in the human body. The twelve organs of Chinese medicine are made up of six solid zang (yin) organs and six hollow Fu (yang) organs. These 12 organs are classified according to the functions of either transformation (yin organs), or transportation
The Zang organs primarily responsible for the creation and storage of Qi and Blood. Each yin organ has a paired yang organ according to their associated element, which has corresponding sense organs and tissues as well as natural associated phenomena
The Zang organs primarily responsible for the creation and storage of Qi and Blood. They are considered most important and consist of: xin-heart, gan-liver, pi-spleen, fei-lung, shen-kidney and pericardium.
Heart (Xin) "Chief of the Vital Organs" regulates the other organs by controlling circulation of blood. The heart also plays an important role in behavior and mental health. The heart activity is reflected on the colour of the face and the tongue.
Liver (Gan) stores and regulates the blood distribution throughout the body and maintains the even flow of Qi both in terms of physical and emotional activities as well as controlling the tendons, manifesting in the nails and opening into the eye.
Spleen (Pi) controls the "moving and transforming" of vital essence extracted by the stomach from food and drink; it houses the mind)
Lungs (Fei) control vital energy (qi) by extracting it from the air and transferring it to the blood. The lung controls respiration, and regulates and promotes water metabolism, but also nourishes the skin and hair.
Kidneys (Shen) control water, stores the essence and thus dominates reproduction, growth, and development.
The pericardium is the least important of the zang organs, which encloses and protects the xin-heart and the diseases of the pericardium result in dysfunction of the xin-heart.

The Fu organs are mainly responsible for receiving, processing, and eliminating substances in the body. They generally only suffer from excess syndromes. They are considered to be closer to the surface of the body, than the Zang.. They are considered less important and consist of: small intestine, large intestine, stomach, gall bladder, urinary bladder and sanjiao. In TCM the functions of the fu organs are very similar to their functions in Western medicine.

In addition to the 12 Zang-fu organs, there are 2 extraordinary organs, the brain and the uterus. Their individual functions are synonymous to Western medicine. However, in TCM they originate and evolve differently and relate in their function to other Zang-fu organs as well as their corresponding meridians.

Five Elements - Wu Xing
The five elements of wood, fire, earth, metal and water - are absolutely necessary for human living and represent the processes that are fundamental to the cycles of nature, and therefore correspond to the human body. An old Chinese medical text describes it as "The 5 elemental energies combine and recombine in innumerable ways to produce and manifest existence. All things contain the 5 elemental energies in various proportions." These five elements interact and counterbalance one and another in two basic cycles known as the creative (sheng) and control (ke) cycles. All the elements are mutually inhibitive and at the same time mutually creative: wood creates fire, fire creates earth, earth creates metal, metal creates water, and water creates wood. Conversely, water inhibits fire, fire inhibits metal, metal inhibits wood, wood inhibits earth, and earth inhibits water.
Each of these elements has corresponding organs, emotions, colours, tastes, tissues, human sounds, and endless other correspondences. Fire corresponds to the Heart, Earth the Spleen, Metal the Lungs, Water the Kidneys, and Wood to the Liver.