Temple Blog Biological Rhythm, and Yin & Yang

Traditional chinese medicine

yin & yang

In Traditional Chinese Medicine (TCM), the theories of Yin & Yang and the 5 Elements are fundamental. They can also be applied to understand biological rhythm.
During one day and one night, there are four periods with Yin and Yang features. The daytime is considered Yang while the night is Yin. The period from early morning to noon is Yang, from noon to evening is Yin of Yang, from evening to midnight is Yin of Yin, and from midnight to early morning is Yang of Yin.

People should comply with the Yin and Yang. How should people abide by the Yin and Yang? It is the correlation between the Yin and Yang and the 5 Elements for the internal organs:

The heart is the Yang of Yang;
The lungs are the Yin of Yang;
The kidneys are the Yin of Yin;
The liver is the Yang of Yin;
The spleen is the outmost Yin of Yin.

circadian rhythm & body clock

The circadian rhythm can be divided into stages such as Yang of Yin, Yang of Yang, Yin of Yang, and Yin of Yin, called “Shaoyang, Taiyang, Taiyin and Shaoyin”.

Every tissue and organ in the body operates according to biological rhythms. The body clock keeps body processes running according to a schedule. The circadian rhythm is a 24-hour cycle that regulates the timing of functions like eating, sleeping, and temperature. The body clock is based on the idea that one can make the most of the energy and specific organs by using them when they’re at their peak.

Based on the TCM, the heart executes the natural state of Yang of Yang, so the requirement on the heart by the body seems most urgent, cardiac burden rises to the highest point, and risks of exhausted heart Qi seem the highest with the highest incidence of morbidity. Blood pressure and heart rate reach their peaks during 11 am to 1 pm (the heart duty time), and so does the incidence of heart diseases such as myocardial infarction, arrhythmia, angina pectoris and sudden cardiac death.
Based on the day and night rhythm, lung diseases most likely occur in the afternoon with a risk of aggravation and death; kidney diseases occur from evening to midnight and liver diseases from midnight to sunrise. It is, therefore, crucial to understand the biological circadian rhythm in TCM.