Diagnosis by Pulse Feeling

Diagnosis by Pulse Feeling in Chinese Traditional Medicine

To cure a disease a correct diagnosis must be made. Many diagnostic means based on advanced technology exist today, but in ancient times physicians had to depend on examining, inquiring, listening, smelling and feeling. Feeling the patient's pulse is an original diagnostic measure of Chinese physicians. Together with other diagnostic methods, pulse feeling is indispensable in obtain­ing the information necessary to differentiating the patient's symp­toms and signs.

Pulse feeling

A Long History

Pulse feeling in China is based on centuries of clinical experi­ence. A chapter in Shi Ji (Records of the Historian) written in 104-91 B.C. tells how the celebrated physician Bian Que, who lived in the 5th century B.C., employed especially the diagnostic method of pulse feeling. Sima Qian, author of the book, wrote: "Bian Que was the first to adopt pulse feeling in this country." This was challenged, however, by other evidence that pulse feeling was prac­tised by physicians before Bian Que. The legendary doctors of prehistoric times Jiudai Ji and Guiyu Qu gave discourses on pulse feeling. Nei Jing (Canon of Medicine) compiled during the Warring States Period (475-221 B.C.) and Nan Jing (Classic of Difficulty) written later carry comprehensive discussions on this method. The books on silk entitled Mai Fa (Methods of Pulse Feeling) and Yin Yang Mai Zheng Hou (Symptoms of the Yin and Yang Pulse Patterns) found in the 2,100-year-old tomb excavated in 1973 near the village of Mawangdui in a suburb of Changsha, Hunan Province, also offer valuable information about the ancient diagnostic technique of pulse feeling. From these evidences we see that pulse feeling as a means of clinical examination was already well systematized into the content of Chinese medicine before the 5th century B.C.

Chunyu Yi (205-? B.C.), also called Cang Gong, another physician whose biography is included in Records of the Historian, studied pulse feeling for three years under Gongcheng Yangqing, who presented Bian Que Mai Shu (Bian Que's Book on Pules) to him. Case records of Chunyu Yi included in Records of the Historian show that he began his examination of a patient by feeling his pulse.

Zhang Zhongjing (150:219), an outstanding physician in the Eastern Han Dynasty, revealed in his Shang Han Za Bing Lun (Treatise on Febrile and Other Diseases) that pulse feeling was already fairly well developed in clinical examinations by his time. China's first book specially devoted to pulse feeling, however, did not appear until Wang Shuhe (180-270) compiled his Mai Jing (Classic on Pulse). This great physician described in detail 24 different patterns of pulse beat and their diagnostic significance. He also discussed various methods of taking the pulse, making it a more practical diagnostic measure. Further works on pulse followed, and physicians began to specialize in this branch of medicine. Notable among them was Li Shizhen (1518-93), who wrote among other books one entitled Bin Hu Mai Xue (Bin Hu's Study on Pulse). It is estimated mat by the beginning of the present century more than 100 works had been written on the pulse. These chronicled the successive stages in the development of this aspect of medicine.

Factors To Be Considered in Pulse Feeling

A knowledge of anatomy and physiology are indispensable in pulse feeling. And in fact valuable references in these fields are found in ancient Chinese medical literature.

First to be considered in pulse feeling is the relation between the heart, blood and blood vessels. The pulse directly reflects the condition of the blood and the heart function. Canon of Medicine describes the blood and blood vessels as controlled by the heart, and the vessels as canals through which the blood flows. It also describes the heart and pulse as co-related. The pulse is described as keeping pace with the heart beat and stopping with cessation of blood circulation when the heart dies. It also points out that nour­ishment absorbed through the digestive system is transmitted to the liver from which it goes to the lungs by way of the heart and then returns to the heart, to be carried to all organs and tissues. Canon of Medicine likens the circulation of blood through the vessels to its coursing through an endless ring. Rudimentary as the theory was, it was highly significant at that early time, serving as a fairly scientific basis for the study of the pulse and its feeling.

The second consideration in pulse feeling is the rate of blood circulation, and physicians in ancient China paid due attention to this factor. Classic of Difficulty noted that blood travels three cun [A cun was then about 2.29 centimetres.] on inhalation and another three cun on exhalation, a total of six cun in one breath. Inaccurate as it was, this observation recog­nized that the rate of blood flow is an important indicator of the condition of blood circulation. Modern clinical examination of patients with cardiovascular disease also usually includes measur­ing the time taken for a round in the systemic and pulmonary circula­tions.

The third consideration is the relation between breathing fre­quency and pulse rate. A passage in Canon of Medicine states that two pulse beats are felt when one inhales and another two follow when one exhales. Or, when an average of 18 breaths are taken per minute, there are 72 pulsations, a 1:4 ratio. The book also gives data on the normal frequency of pulse rate that conforms with mod­ern physiological observations. Canon mentions too that dis­proportion between the frequency of breathing and that of circula­tion suggests abnormality. According to the ancient physicians, the ratio of 1:2 or, at the other extreme 1:6 pulsations for a breath indicate disease. As is known, the ratio between these frequen­cies reflects the co-ordination between heart and lung functions. In clinical practice we often see patients with fluctuations in pulse revealing arrhythmia arising from abnormal pulmonary circulation and lack of oxygen in arterial blood.

The ideal site for pulse feeling is the fourth consideration. There was a very long period of probing to find this. The ear­liest practice was feeling at all arteries where a pulse could be felt, including those on the head, at the neck and cheeks, as well as the radial arteries in the arms and the posterior tibial, dorsal pedal, popliteal and femoral arteries of the legs. These are the hypodermic arteries and those over the bones. It is mainly this type of pulse feeling that was dealt with in Canon. There is also the “three-site pulse feeling,” which is done at the temporal, radial and dorsal pedal arteries. The latter is practised in modern medicine and is generally termed radial-artery pulse feeling. It involves the radial artery at the radial styloid process only. Discourses on this particular type of pulse feeling can be found in such medical works as Classic of Difficulty and Classic on Pulse as well as Canon of Medicine.

Though rarely used, general pulse feeling has not been discard­ed. Because the pulse wave or blood pressure arising from the contraction of the heart is transmitted through the arteries to all parts of the body, fluctuation occurs in this pressure corresponding to alterations in the condition of the circulatory system and indicates heart function and the elasticity of the artery walls. Taking the pulse at more than one site therefore enables the doctor to obtain a more reliable and extensive basis for diagnosis. Local anaemia in the arms or legs, for example, resulting from defects at such main arteries as the aortic arch will make pulse feeling in the extremities difficult. Pathology of the blood vessels can therefore be affirmed by general pulse feeling, which is also useful in diagnosing cardiopathy or thrombotic arteritis.

Other factors involved in pulse feeling are listed in Canon of Medicine as time of day, recommending morning as best, when vital energies function in balance; seasonal changes; disposition, constitution, weight and mental state, pointing out that fear, worry and physical exertion cause fluctuation in pulse. Later medical writings mention such factors as sex, age and build. Modern physiol­ogy attributes various factors as affecting heart function, i.e. pulse rate and blood supply. Blood supply, for example, is usually stable after a night’s rest. Affecting the volume of blood delivered by the heart are also sex, age, posture, activity and mental state. The conclusion can therefore be drawn that the Chinese physicians in ancient times made elaborate observations necessary in differenti­ating normal from abnormal pulses.

Clinical Significance of Pulse Feeling

Ancient Chinese medical practitioners were enabled by pulse feeling to know whether a disease was “cold” or “warm” in nature and whether the patient’s vital energy was growing or declining. They were able also to determine the cause of a disease, the part of the body affected, and prognostic signs. Canon of Medicine points out that every physician should be skilled in pulse feeling as an aid in judging whether a disease is fatal, and if it is not, in drawing up his therapeutic plan so as to regulate the body energy and restore the patient to health. It also states that the pulse pattern indicates not only the visceral origin of a disease but also its basic cause. This formula stems from the concept that the human body should be view­ed as a whole, based on a theory in Chinese traditional medicine that channels and collaterals in the body are routes along which vital energy circulates and which connect the visceral organs with the extremities, muscles, skin and joints, into an organic whole. The pulse, then, as part of the whole reflects physiological changes within the whole. Canon’s affirmation that “what exists inside will inevi­tably be detected from outside” summarizes this concept concisely.

Pulse is a significant indicator of the functioning of the circula­tory system. It indicates whether or not the aortic valve of the heart is functioning normally and the beat is in proper rhythm, also the elasticity of the arteries. Moreover, the circulatory system is so closely related to the various visceral organs that any change in the metabolism of the tissues arid any major abnormalities in the organ­ism will affect blood circulation. The pulse pattern represents therefore not only changes in the circulatory system itself but also those in the other systems and individual organs. Fever and inflam­mation will produce-an increased number of white blood corpuscles; hepatocarcinoma, diabetes and certain other diseases will cause struc­tural change in the blood which in turn induces alteration in the pulse pattern. The nervous system is the most closely related to the cir­culatory. This is manifest in the blood vessels being subject to functional changes in the sympathetic and accessory sympathetic nerves, which control the blood vessel walls — changes that occur in a disease. The ancient Chinese physicians were on the right track to rely heavily on pulse feeling in diagnosis, as we can see, though they understandably did it quite empirically.

Pulse pattern, or characteristics of pulse as felt by the doctor, includes depth, rate, force, rhythm, etc. A healthy person’s pulse is normal in these respects arid is termed by Chinese physicians mean pulse. A sick person has a symptomatic pulse, varying in different diseases. Ancient Chinese practitioners did elaborate research into pulse patterns, more than a dozen different patterns being described in Canon of Medicine, 24 in Classic on Pulse and 30 or more in later medical works. Of special interest is the book entitled Cha Bing Zhi Nan (Guide to Diagnosis) written in 1241 by Shi Fa, which con­tains 33 diagrams symbolizing different pulse patterns. Modern diagrams of pulse patterns date only from 1860 when the French physician Etienne Jules Marey invented the sphygmograph, while centuries before that invention the Chinese doctors had drawn equal­ly elaborate sphygmographic diagrams simply by feeling the pulse of the patients.

Of the two dozen or so pulse patterns generally listed in ancient medical works, we shall discuss the following.

The “floating” and “sinking” pulses, first mentioned in Canon of Medicine and elaborated on in Classic of Difficulty and Treatise on Febrile and Other Diseases, differ in depth — that is, the specific depth of the optimal site for feeling the pulse. A “floating” pulse is one easily felt when the doctor presses the patient’s artery lightly but weakens when he presses it harder. This pattern usually suggests “external” disease, that is, conflict between the organism and external pathological factors, a phenomenon characteristic of certain diseases in their early stage. In physio-pathological language, such a pulse is in most cases due to weakening of the blood vessels’ elasticity and resistance, as well as to relaxation of the radial artery resulting from increased blood supply from the heart and acceleration of blood cir­culation. A “sinking” pulse is one felt only when the artery is pressed fairly forcibly and indicates “internal” feebleness. Resulting from de­creased blood supply, low blood pressure, little blood passing through the artery endings and stronger resistance to circulation from the blood vessel walls, this pattern may be taken as a symptom of heart disease.

Pulse may be felt as “retarded” or “rapid”. First mentioned in Canon of Medicine and then in other classics, the concept refers to the pulse rate. A pulse rate of less than 60 beats per minute is referred to as retarded and points to a disease “cold” in nature. Modern researchers attribute such abnormality in blood circulation to over-excitement of the vagus nerve and obstruction in atrium-ventricle transmission. A disorder “warm” in nature, or hyper-function of the organism, is indicated by rapid pulse, over 90 beats per minute.

What Canon of Medicine calls “intermittent” pulse is referred to in modern diagnostics as bigeminal, trigeminal or quadrigeminal pulse. This is characterized by several slow beats followed by an interruption of equal length and suggests obstruction in metabolism (resulting from heart disease), heart failure or crisis in the function of the organism. Canon notes that such a pulse pattern indicates feebleness of visceral organs, an observation not remote from modern theories.

The concept of “slipped” or “rough” pulse refers to abnormal fluctuation in rhythm. A “slippery” pulse, first mentioned in Canon of Medicine, was described in Classic on Pulse as “fluid”, while the celebrated physician Sun Simiao (581-682) compared it to “a stream of pearls”. “Slippery” pulse indicates hyperthyroidism, arteriosclero­sis or other diseases with such symptoms as accelerated metabolism and vascular expansion-contraction, as well as over-fluency of the blood. This occurs normally after the third month of pregnancy, suggesting increased volume and supply of blood. Chinese doctors long ago felt the pulse as a pregnancy test.

A “rough” pulse is described in Canon of Medicine as “staggering along a rugged road” and “symptom of heart pain”. This may indicate either a lack of vital energy, or circulatory obstruction arising from excitement, indigestion or excess secretion in the respiratory tract. Anaemia, hemorrhage, or heart dysfunction which decreases the supply and retards the flow of blood usually cause this “rough” pulse pattern.

Ancient Chinese physicians summarized their experiences in pulse feeling:

A case of intoxication is easily curable when the patient’s pulse is full, critical when it is weak; a case of obstruction or stasis in blood circulation in the abdomen is easily curable when the patient’s pulse is smooth, critical when it is feeble; a case of apoplexy is easily curable when the patient’s pulse is floating and retarded, critical when it is full and rapid.

They also listed various patterns of pulse indicating various diseases. All their records remain valuable in modem medicine, for ascer­taining the cause, pattern, trend and aftermath of a disease.

Pulse feeling is not to be taken as a total diagnostic means, how­ever. The ancient medical works were correct in stressing that pulse feeling should be practised in co-ordination with examination, auscultation, smelling and enquiring.

Pulse Feeling Across China’s Borders

There has been a very long history of the Chinese skill of pulse feeling introduced into various foreign countries. Such medical classics as Canon of Medicine and Classic on Pulse containing dis­courses on pulse feeling were taken to Japan and other neighbour countries of China as early as the beginning of the 7th century. Ac­cording to sources quoted in History of Japanese Medicine by Fukuji Fujikawa, the Japanese Buddhist monks E-Nichi and Fukuyin who had come to China as students carried Chinese medical works with them when they returned in 632. In 702 the Japanese government in its Decree on Medicine listed Classic on Pulse among medical textbooks.

Researchers claim that Chinese impact is evident in the volumi­nous Arabic work Canon by the celebrated physician Abu Ali al-Husain ibn Abdula ibn Sina (Avicenna) with respect to knowledge on pulse.

The Chinese skill of pulse feeling was introduced into Persia in. the 14th century when an encyclopaedia published there included discourses on Chinese medicine and particularly pulse feeling. The work also mentioned the Chinese Classic on Pulse and its author Wang Shu Khu (Wang Shuhe). The 17th-century Polish physician Michael Boym, who had visited China, had published in 1686 his illustrated book entitled Clavis medica ad Chinarum doctrinam de pulsibus — a book which had first appeared in 1682 under the title Andreas Cleyer. Special mention should be made of the work of the noted English physician John Floyer (1649-1734), who did research on pulse, quite evidently using his knowledge of Chinese traditional medical science. He also invented an instrument with which the doctor could measure a patient’s pulse, and wrote The Physician’s Pulse-Watch, an essay explaining the old art of feeling the pulse and improving it with the aid of his pulse-watch. This was published in London in 1707. Floyer’s invention and book are considered by Western scientists as of great historical significance.

The spread of Chinese knowledge on pulse continued on from the 17th century, with more than a dozen works in this field translat­ed into a number of Western languages.