Spring

"The three months of the spring season bring about the revitalization of all things in nature.  It is the time of birth.  This is when heaven and earth are reborn.  During this season it is advisable to retire early.  Arise early also and go walking in order to absorb the fresh, invigorating energy.  Since this is the season in which the universal energy begins anew and rejuvenates, one should attempt to correspond to it directly by being open and unsuppressed, both physically and emotionally. 

On the physical level it is good to exercise more frequently and wear loose-fitting clothing.  This is the time to do stretching exercises to loosen up the tendons and muscles.  Emotionally, it is good to develop equanimity.  This is because spring is the season of the liver, and indulgence in anger, frustration, depression, sadness, or any excess emotion can injure the liver.  Furthermore, violating the natural order of spring will cause cold disease, illness inflicted by atmospheric cold, during summer." 

~ Huang Di Nei Jing (The Yellow Emperor's Classic of Medicine)

The Yellow Emperor’s Classic of Internal Medicine, also known as Huangdi Neijing or simply Neijing, is one of the earliest ancient Chinese medical texts. The book has been accredited to the Yellow Emperor Huang Di who lived at around 2500 BC. This book is composed of 2 parts, where each is composed of eighty-one chapters. It is written is a question-and-answer format between Huang Di and his six legendary ministers. The Yellow Emperor’s Classic firstly discusses and explains the fundamentals of ancient Chinese medicine in the first part, the Suwen. The second part, the Lingshu, refers to the acupuncture therapy in great detail.

The Yellow Emperor’s Class of Internal Medicine is a book which has enlightened us about the fundamentals of ancient Chinese medicine and the complex therapy of acupuncture, designed by Bian Que. The Ancient Chinese believed, according to the Yellow Emperor’s Classic, that the Chinese believed that diseases were due to diet, lifestyle, emotions, environment and age, instead of demons. This is still what we believe in modern times with some diseases. Therefore, the book is revolutionizing in the sense that the Chinese developed our beliefs (to a certain extent) over 2300 years ago.

http://www.med-street.com/history-of-medicine/2600-bc-1-bc/