Objectives : The purpose of this paper is to investigate the mechanism of ‘Joy impairs the Heart’.
Methods : Huangdineijing was searched in relation to ‘Joy’ and ‘Heart’, then Joy was divided into physiological and pathological joy. After examination of the similarities and differences between the two, the mechanism of ‘Joy impairs the Heart’ was drawn out.
Results : 1. Excessive Joy not only relaxes Qi(氣), but also disperses Shen(神). 2. Impairment of Heart damages heart locally and Impairment of Yang not only damages Qi or Shen focally, but also damages Yang of the whole body and the degree of damage is thought to be more extensive than “Joy impairs the Heart”. 3. “Too much joy and pleasure can cause the Shen(神) to scatter and not remain stored.” not only relaxes Qi, but also disperses Shen(神), and the degree of damage is less than “Sudden joy damages Yang”. Conclusions : Excessive or Sudden Joy impairs the Heart by disturbing Heart’s property of maintaining Taiyang by scattering Shen(神) or not maintaining high Yang density. Forced expression of Joy impairs the Heart by relaxing and stagnating Qi.