Shuang Liu Jiangxue Zhou Jilin Wang Yingxia Sun

Abstract: In this paper, we analyze the implications and extensions of the concept of needle sickness ［i.e., fainting during acupuncture treatment］ by combing through ancient and modern literature on needle sickness and combining it with clinical practice. 〖JP2〗We propose that needle sickness is a common reaction to acupuncture stimulation when the body is in a state of “spirit-qi vacuity” (subpar physical and mental states such as hunger, fatigue, and mental tension). It should be regarded as a special reaction to gaining qi. This change in understanding will certainly have a significant impact on clinical practice.

Keywords: Needle sickness; concept of needle sickness; obtaining qi; conceptual research

Needle sickness ［i.e., fainting during acupuncture treatment］ is a commonly observed response to needling in the clinical practice of acupuncture. Various editions of textbooks and research studies on this subject classify needle sickness as an abnormal response to acupuncture needling^{［1-2］ ［3］}. Needle sickness is considered to fall within the scope of acupuncture needling safety issues and is defined as an adverse event, adverse reaction^［4］, acupuncture incident, or acupuncture accident. Most sources take a negative stance and state that this reaction should be avoided if possible. Modern research tends to focus on describing the causes and manifestations of needle sickness, as well as how to handle it, with very little exploration of the link between needle sickness and treatment effects. A literature search revealed that as early as the Qing dynasty, Li Shouxian’s text Zhenjiu Yixue ［Easy-to-Learn Acupuncture and Moxibustion］ explicitly stated that “［a patient who experiences］ needle sickness will definitely have a great ［treatment］ effect”, but this did not attract enough attention. In recent years, there have been numerous reports of enhanced treatment effects after needle sickness and the viewpoint that needle sickness has synergistic effects has been discussed multiple times by different scholars. In 2004, Professor Greenwood proposed that the synergistic effects of needle sickness would trigger a major revolution in empirical knowledge.^［5］

Implications of the concept of needle sickness

Ancient and modern understandings of the concept of needle sickness

Needle sickness is defined as the phenomenon of fainting during the process of acupuncture needling, and its clinical manifestations may be either mild or severe. Mild needle sickness manifests with lassitude of essence-spirit, dizziness, and nausea with a desire to vomit. Severe needle sickness manifests with flusteredness, shortness of breath, a somber white facial complexion, cold sweat, and a fine and weak pulse; there may even be symptoms like coma, green-blue or purple lips and nails, a drop in blood pressure, fecal and urinary incontinence, and a faint pulse verging on expiry^［1］. Early literature describes the manifestation of needle sickness as “collapse”; for instance, chapter 10 of Lingshu ［The Magic Pivot］, entitled “Channel Vessels”, states: “［when］ draining … then ［there is］ collapse”. The text Jin Zhen Fu ［Ode to the Golden Needle］was the first to use the term “needle sickness”, saying that “one who ［experiences］ needle sickness ［has］ spirit-qi vacuity”. This text considers the root cause of needle sickness to be a state of “spirit-qi vacuity”. Scholars outside of China have referred to needle sickness using terminology such as needle shock, acupuncture syncope, reflex syncope, vasovagal syncope, vasovagal shock, or vasomotor reflex［7］. It is clear that many scholars outside of China endorse the idea that needle sickness is a vasovagal response, but there is some disagreement regarding the specific clinical manifestations, as they use terms like “syncope”, “shock”, and “reflex” to define needle sickness. Ancient and modern understandings of the causes of needle sickness are essentially the same; it is mainly associated with the state of the patient’s body (subpar physical and mental states such as hunger, fatigue, and mental tension) and excessively vigorous manipulation by the practitioner.

Elaborating upon the concept of needle sickness

Most editions of textbooks and authoritative dictionaries define needle sickness as the phenomenon of syncope during the course of acupuncture needling (see Table 1); only Zhonghua Yixue Baike Quanshu ［The Chinese Medical Encyclopedia］defines it as a series of symptoms. While the objectives of the former differ from those of the latter, the former texts also provide descriptions of other clinical manifestations of the needle sickness reaction in later passages, so they actually confirm that the needle sickness reaction is a series of symptoms. In addition, mild needle sickness reactions are more commonly seen in clinical practice, while those that manifest with “syncope” are relatively rare; a literature search only found a handful of reports on the latter reaction^［12］and there were no reports of severe adverse consequences caused by needle sickness^［13］. The 2017 edition of Yixue Baike Quanshu ［The Chinese Medical Encyclopedia］^［11］defines needle sickness as a series of symptoms that include dizziness, nausea, sweating, and even fainting, thereby emphasizing the variable and concurrent nature of needle sickness symptoms while also clarifying that there are mild and severe cases. In the same year, Christensen et al.^［7］ proposed that the use of terminology such as “syncope” and “shock” to describe needle sickness is not sufficiently accurate and may even be an overexaggeration, as these terms can cause patients to feel anxious and fearful. Therefore, the authors of the present work believe that definitions of needle sickness should include the clinical manifestations of at least 2 different levels of severity, namely the dizziness and nausea of mild needle sickness reactions and the flusteredness, cold sweat, and fainting of severe needle sickness reactions. Moreover, the objective should be to convey that there is a series of symptoms or reactions. Modern research has proven that there is a strong correlation between the causes of needle sickness and the state of the patient’s body. Scholars have used methods from evidence-based medicine to summarize 348 cases of needle sickness; in 347 of these cases, the needle sickness was caused by subpar mental or physical conditions, and only 1 was caused by excessively vigorous manipulation^［14］. The authors believe that the strength of needle manipulation is a relative concept with a certain degree of individual variation, so there is no way to correctly define gentle or vigorous manipulation; thus, there is a certain degree of relativity regarding excessively vigorous manipulation as a cause. In light of this, the present paper proposes that internal causes due to the state of the patient’s body at the time play the leading role.

Surveying ancient and modern literature, there is significant disagreement on whether or not to remove the needles when responding to needle sickness. Ancient literature, represented by Zhenjiu Dacheng［The Great Compendium of Acupuncture and Moxibustion］, emphasizes that one must not remove the needles after needle sickness occurs; the chapter entitled “Draining and Supplementing ［Techniques］ of Li from Nanfeng”^［15］states: “for all ［cases of］ needle sickness ［…］ ［one］ must not remove the needles ［…］ removing the needles will harm the patient”. This text claims that removing the needles after needle sickness will further exhaust the qi and cause severe adverse consequences that will “harm the patient”. In contrast, modern literature such as Zhenjiuxue ［The Study of Acupuncture and Moxibustion］and authoritative dictionaries claim that one must immediately remove the needles after needle sickness occurs. The reason for this disagreement may be due to a difference in focus; the ancients paid more attention to the effects of needling in cases of needle sickness and believed that removing the needles would affect the treatment results, so they adopted practices such as not removing the needles and “needling the frog flesh ［i.e., the prominence of the bicep muscle］”. Meanwhile, in modern times people are more concerned about the patient’s physical state of discomfort, so they remove the needles to eliminate this state; this serves to stop the needle stimulation and enables the patient to rest in an appropriate position.

Another noteworthy issue is the fact that none of the aforementioned dictionaries and textbooks mentioned the link between needle sickness and treatment effects, ignoring the potential harm or benefit that needle sickness may contribute to the clinical efficacy of the treatment. Their stance on needle sickness is restricted to the attitude of patients towards needle sickness, so they take a negative view of the phenomenon (see Table 1).

Table 1. Concepts of needle sickness

Extensions of the concept of needle sickness

Comparison of needle sickness and abnormal responses to acupuncture needling

Various editions of Zhenjiuxue［The Study of Acupuncture and Moxibustion］and Cifa Jiufa Xue ［The Study of Needling and Moxibustion Methods］classify the phenomenon of needle sickness as an abnormal response to acupuncture needling. An abnormal response, as opposed to a normal one, implies that this type of situation happens relatively rarely in acupuncture treatments. Aside from needle sickness, this type of situation includes stuck needles, bent needles, broken needles, hematoma, puncturing internal organs, puncturing the cerebrospinal tract, and peripheral nerve injuries. Among these, needle sickness, stuck needles, bent needles, and hematoma are relatively common; if treated in time, patients can typically recover from these conditions on their own, so they present less of a hazard to patients. A stuck needle can also be used as part of a special technique to treat soft tissue disorders. Puncturing internal organs, puncturing the cerebrospinal tract, and peripheral nerve injuries tend to cause adverse effects and present a more serious hazard to patients, and the majority of these situations are caused by inappropriate needling practices. While both types of situation are classified as abnormal responses to acupuncture needling, they differ greatly in terms of the level of harm and causes. The latter type of situation unquestionably falls within the scope of needling safety issues.

Comparison of needle sickness and needling safety issues

Acupuncture needling safety issues can be classified as adverse needling events, adverse reactions to needling, needling incidents, needling accidents, and needling complications^［16］. Most modern literature categorizes needle sickness among the aforementioned incidents in order to evaluate the safety of acupuncture needling. Should needle sickness be included under the concept of acupuncture needling safety? Taking into account the previous discussion of the implications and causes of needle sickness, this question may be analyzed as follows: (1) The occurrence of needle sickness is related to the state of the patient’s body and the amount of needle stimulation, but there is some degree of individual variation, so it is not necessarily caused by the treatment; therefore, it is not caused by needling alone. In addition, there is a chance that it may happen even when following standard practices, so it is not due to external factors or accidental causes. (2) Regarding the causes of needle sickness, it is possible to foresee and avoid them to some degree. (3) Patients can recover from needle sickness reactions if the practitioner responds promptly and the final outcome will not impact treatment effects, or may even enhance them. Through a comparison with concepts of acupuncture needling safety (see Table 2), it is clear that needle sickness does not conform to these concepts.

Table 2. Acupuncture needling safety concepts

From a comprehensive comparison between the features of the concepts of needling safety and needle sickness, it would be too simple to relegate needle sickness to the scope of needling safety issues, as it is not completely aligned with the concept of needling safety. As needling is an invasive therapy, it can cause some discomfort in the body; whether or not this discomfort is considered “adverse” must be judged based on whether the end result of the treatment aligns with the goals of acupuncture needling^［17］. Therefore, the key to determining the nature of needle sickness is whether or not the end result after needle sickness occurs aligns with the treatment goals.

Real cases of synergistic effects from needle sickness

The text Jin Zhen Fu, published in 1439, was the first to use the term “needle sickness”, but there was no mention of the relationship between needle sickness and treatment effects until 1798, when the text Zhenjiu Yixue clearly stated that “［a patient who experiences］ needle sickness will definitely have a great ［treatment］ effect”. From this point, later generations of practitioners discovered numerous cases in which needle sickness had synergistic effects. In her text Xin Zhenjiu ［New Acupuncture and Moxibustion］, published in 1954, modern acupuncture scholar Zhu Lian recorded a case of intractable enuresis that resolved completely after needle sickness. In 1981, a practitioner in Fujian province with the surname Zheng^［18］was treating a patient with “facial muscle spasm” who had not eaten anything prior to treatment and a needle sickness reaction occurred. After the needle sickness symptoms subsided, no spasms or jerking movements were observed in the facial muscles, which was a clear improvement compared to the previous 3 treatments, and a follow-up 3 months later found that the issue had not reoccurred. In 2011, a practitioner in Henan province with the surname Feng^［19］reported 4 cases of needle sickness; in each of these 4 cases, all of the patient’s symptoms disappeared after the needle sickness subsided. Among them, there was 1 case of a patient with “diaphragm muscle spasms”; after Zhongwan ［CV-12］ was needled, the needle sensation surged upward to the throat and a needle sickness reaction occurred. After the needle was removed and the patient lay flat in the supine position, the hiccups, gastric distention, and other symptoms all vanished, and the patient was cured in 1 treatment. In 2015, a practitioner in Beijing with the surname Jiang^［20］reported 4 cases of improved treatment effects after needle sickness; the results of 1 treatment were equivalent to those of 3-5 typical sessions, which significantly shortened the course of treatment. In one case, a patient who had headaches for 5 years was cured in 1 treatment after experiencing needle sickness and a follow-up 1 year later found no recurrence. In recent years, there have been repeated reports of cases with synergistic effects from needle sickness both in China and abroad. In 2017, Christensen et al.^［7］reported 3 cases of synergistic effects following needle sickness; for all 3 patients, it was their first experience with acupuncture and they all had various levels of mental stress. After recovering from needle sickness, the pain in the 3 patients’ head, neck, shoulders, and back decreased and their range of motion returned to normal. Cases with synergistic effects from needle sickness further demonstrate that needle sickness cannot simply be classified within the scope of abnormal situations or acupuncture needling safety issues.

Needle sickness is a special type of reaction to obtaining qi

Manifestations of needle sickness conform to the diversity of reactions to obtaining qi

Reactions to obtaining qi may vary and needle sickness conforms to the manifestations of these reactions. Obtaining qi refers to the physical state of qi arriving under the needle after the needle has been inserted, which plays a critical role in the treatment that follows^［21］. Obtaining qi is also referred to as “needle sensation”, and was called the “arrival of qi” in ancient times. From the practitioner’s perspective, there are many types of needle sensation, such as sinking, tightness, roughness, and stagnation. From the patient’s perspective, these sensations are even more complex and varied. The only needle sensations recorded in Su Wen ［Elementary Questions］are related to heat and cold; by the Qing dynasty, sensations such as soreness, numbness, and pain were added. At present, recognized needle sensations include several singular or more complex compound sensations such as aching, distending pain, heaviness, numbness, coolness, heat, itchiness, convulsions, or a feeling of insects crawling on the skin^［22］. Professor Wang Xinming claimed that needle sickness reactions with brief periods of dizziness, nausea, and sweating are also reactions to obtaining qi. Wang proposed that the phenomenon of obtaining qi is the process of mobilizing the functions of the whole body, which is also a process that consumes qi; if the patient uses up too much qi, this manifests as needle sickness^［25］.

Chapter 1 of Ling Shu, entitled “The 9 Needles and 12 Sources”, states: “The key to needling ［is］ that the arrival of qi ［makes the treatment］ effective”. This emphasizes that the arrival of qi is the key reason for the effectiveness of acupuncture needling. Viewing needle sickness as a special type of reaction to obtaining qi allows for a better understanding of Li Shouxian’s statement in the chapter “On Needle Sickness” in Zhenjiu Yixue^［26］: “［a patient who experiences］ needle sickness will definitely have a great ［treatment］ effect; this is because of the peaceful interaction of blood and qi”. Needle sickness accelerates the process of the“peaceful interaction of blood and qi”, and this interaction also serves as the “arrival of qi”. This is what is meant by the saying that “if qi arrives quickly, results will occur quickly; if the qi arrives slowly, results will occur slowly”. Thus, patients who experience needle sickness get results quickly after recovering from needle sickness. The discussion on “recovering from needle sickness” in Huang Zhuzhai’s modern text Zhenjiu Jingxue Tukao ［An Illustrated Book of Acupuncture Channels and Points］^［27］agrees with Li Shouxian’s viewpoint. The large number of cases in which needle sickness caused synergistic effects reported in modern research also corroborate this viewpoint from a therapeutic perspective.

Sakai et al.^［28］discovered that obtaining qi increased the power of all bands of brain waves except for the gamma band; there was a strong correlation between the sensation of obtaining qi and changes in the patient’s brain waves. Yin et al.^［29］claimed that there are synchronous correlations between changes in brain waves and the sensation of obtaining qi. Kwon et al.^［30］found that there were 2 explosive increases in the absolute power of the brain wave signals of a patient experiencing needle sickness: the first was after qi was obtained following needling, and the second was after the needle sickness occurred. This showed that the patient’s brain wave signals when needle sickness occurred were similar to those at the time of obtaining qi.

Most current perspectives consider needle sickness to be a type of vasovagal response (VVR), which is caused by the vagus nerve and changes in vascular tone. For example, Christensen et al. and other scholars outside of China refer to needle sickness as an acupuncture-associated vasovagal response. VVR is a common clinical manifestation of an autonomic nervous reflex that occurs under conditions of psychological or physiological stress. Mild cases manifest with the warning signs of needle sickness, while moderate and severe cases manifest with loss of consciousness. Fainting due to causes such as blood phobia, needle phobia, long periods of standing, and emotional agitation is classified in this category^［31］. Some of the effects of the channels and network vessels are closely related to the vagus nerve; a large body of research has proven that acupuncture needling can achieve treatment results through regulation of the vagus nerve^［32］. Research has shown that electroacupuncture on points on the heart channel can regulate the vagus nerve and the sympathetic nervous system to effectively decrease myocardial oxygen consumption and improve myocardial ischemia^［33］. Chen et al.^［34］claimed that stimulation from needling tones the vagus nerve, enhances the balance of sympathetic/vagus nerve activity, lowers serum myocardial enzyme levels, and reduces myocardial damage. The needle sickness reaction can also excite the vagus nerve; the manifestations of bradycardia and hypotension are consistent with a vagus nerve effect caused by acupuncture needling.

In summary, the authors believe that needle sickness is a special type of reaction to obtaining qi. It has the characteristics of a reaction to obtaining qi, but it differs from common reactions to obtaining qi; most subjects who experience a needle sickness reaction to obtaining qi are in a special state of “essence-spirit vacuity”.

Clinical significance and looking to the future

With modern technological advances and improvements in the quality of research, the depth of research on acupuncture has gradually increased, and the understanding of the needle sickness reaction has changed accordingly. A growing number of scholars have recognized that needle sickness can have unexpected synergistic effects that align with initial impressions of needle sickness, i.e. “［a patient who experiences］ needle sickness will definitely have a great ［treatment］ effect”. Scholars have also 〖JP2〗attempted to explore its mechanism, though there are different viewpoints on this topic^［35-36］. This paper considers the needle sickness reaction to conform to the diverse manifestations of obtaining qi and the synergistic effects of needle sickness are also consistent with the effects of obtaining qi, so needle sickness can be viewed as a special type of reaction to obtaining qi, namely one that occurs in response to needling stimulation when the body is in a special state of “essence-spirit vacuity”. Based on a comprehensive analysis of the characteristics of needle sickness, it should not be categorized within the scope of acupuncture safety. In terms of how to respond to needle sickness, one can choose not to remove the needles in mild or moderate cases as long as they do not affect the patient’s ability to lie flat in the supine position. In addition, after Ni Chunhui and other scholars^［37］recognized the impact of the “synergistic effects of needle sickness”, they actively explored “needle sickness therapy” in clinical practice. Using methods such as psychological suggestion and passive motion acupuncture techniques, they induced “critical needle sickness”, i.e. mild needle sickness, with the aim of improving clinical efficacy. Unfortunately, no follow-up reports on this research have been found, but this attempt is still noteworthy. It is possible that the patients’ experience in this process was negative and may even have caused fear, which limited research on needle sickness. At present, we are still in the initial phase of understanding the mechanisms of needle sickness; the vast majority of research results consist mainly of inferential hypotheses. In order to gain a more objective understanding of the mechanisms of needle sickness and its synergistic effects, more empirical research is needed.

Author information:

Dr, Zhao Zhongzhen， Former deputy dean and professor of the School of Chinese Medicine of Hong Kong Baptist University, distinguished professor of Beijing University of Chinese Medicine, and founding director of the Compendium of Materia Medica Research Institute.

Dr. Li Liang Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong.

Dr. Eric Brand Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong.

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