Medical science has the aim of finding out how to strengthen and preserve the health of the human body and how to reduce and conquer disease so that mankind may enjoy health and longevity. This is the lofty aim and immense value of existence of all varieties of medical science. They would be completely unworthy of the title of medical science if they should be divorced from this aim.

According to traditional Chinese medical practitioners'understanding of the human body, a girl reaches puberty at the age of 14 while a boy does so at 16. Then they arrive at the summit of sexual maturity respectively at the age of 28 (for the female) and 32 (for the male). After that, their physical strength descends with the increase in age. The so-called exercise for people of the right age is no other than physical exercise within measure for a certain age group in terms of strenuosity and amount. It should be kept in mind that the aim of taking physical exercises for aging people is, in the eyes of traditional Chinese medical practitioners, not to train their bodies, but to preserve their health. This is also the case with the restraint of the sexual affair. When a woman has reached 42 in age and when a man has become 48 years old, their physiological functions will begin to decline; therefore, they should rein in their sexual desire, so as to avoid too heavy a drain on their strength.

Disease is the archenemy of longevity. People who want to enjoy good health and a long life must guard against disease, and have the diseases that they have unfortunately contracted correctly treated and promptly cured. They should never look for doctors or hospitals haphazardly or adopt wrong principles and methods of treatment. The following is about proverbial sayings in traditional Chinese medicine which represent a sum-up of valuable experience in prevention and cure of diseases and so are worthy of serous study and application.

Disease arises from excessive employment. This is a maxim in the Classic of Internal Medicine. It expresses an important view in the etiology of traditional Chinese medicine and also a fundamental principle in the science of health preservation. It tells us that in order to be healthy and long-lived people must pay attention to the need of doing work and taking rest both in moderate amounts, because the incidence of a number of diseases is due to engaging in labor, indulging in drinking and eating or doing physical or mental exercises in amounts in excess of normal limits.

China's traditional way of health preservation has developed through the accumulated wisdom and experience of thousands of years, and is known throughout the world for its distinctive methods and effects. These methods are often closely related to the daily life of the people. They are simple, safe and effective, as well as being easy to understand and learn.