Developed over and practiced for thousands of years, traditional Chinese medicine (TCM) teaches us that we all have qi (chi) flowing through us. In order to understand meridians, one must first have a basic understanding of qi. Qi is a life force or energy which flows into, through, and out of each person, interacting with the physiological body, the mind, the spirit, and other energies in the environment. A balanced qi leads to good health and mental wellbeing, but an unbalanced qi causes physical maladies, illness, pain, depression, anxiety, and anger.

Emotional, environmental, and physical factors can all cause imbalances in qi. These factors include stress or overreactions, heat or cold, humidity or dryness, and poor diet or overworking. If qi becomes unbalanced, weak, or stagnate due to any of these factors, it can lead to physical and emotional illness.

Meridians, traditionally called jing luo, are the pathways in the body through which qi or energy flows. TCM practitioners envision meridians as a network of rivers and streams flowing through the body either upward or downward. Although meridians are not visible to the naked eye, TCM practitioners, yogis, and sages have sensed and mapped the body's meridians through trial and error practice and while in deep meditation.

Twelve meridians known as the Principal Meridians flow through the body. Each of these meridians is associated with an organ system and an element. Each is also divided into a yin and a yang association with the yang meridians flowing downwards, and the yin meridians moving upwards through the body.

The Principal Meridians are as follows:

1. Kidneys (yin/water)
2. Liver (yin/wood)
3. Spleen (yin/earth)
4. Heart (yin/fire)
5. Lungs (yin/metal)
6. Pericardium (yin/fire)
7. Bladder (yang/water)
8. Gallbladder (yang/wood)
9. Stomach (yang/earth)
10. Large Intestine (yang/metal)
11. Small Intestine (yang/fire)
12. Triple Warmer (yang/fire)

In addition, eight Extraordinary Meridians correspond to the twelve main meridians. TCM practitioners believe these eight corresponding meridians (the Yin Chiao, Yang Wei, Yin Wei, Chong, Dai, Ren, and Du) act as reservoirs or pools of qi which supply the Principal Meridians with energy.

Along all of these meridians lay over 400 acupuncture points. These points mark places along the meridians where energy flows closest to the surface of the skin. At these points, acupuncturists can remove blockages, weaknesses, stagnant energy, and balance energy throughout the body, thereby promoting overall health and wellbeing.

Sources:

Acupuncture-Meridians (2014). Acupuncture Points and Meridians.

MedicineNet (2014). Acupuncture.