Heavy dampness is the body has dampness evil invasion, including the two categories of external dampness and internal dampness. When external dampness is heavy, there is no obvious characteristic of yin and yang weakness. Internal dampness, on the other hand, is mostly related to yang deficiency, especially spleen yang deficiency, which is prone to produce heavy dampness in the body. The patient feels the external dampness evil and is mainly characterized by superficial symptoms, such as heavy limb sleepiness (weakness and sinking of the limbs), aches and pains, eczema in the body, itching, abnormalities in the bring-down, etc. The pulse is mainly floating and slow, mostly due to rain showers and humid environment. This kind of external dampness has no specific relationship with the deficiency of yin and yang of the body, but feeling external evils for a long time has not been treated in time, which can easily cause dampness from the outside to the inside. The patient’s internal dampness is mostly related to yang deficiency. Especially when spleen yang is deficient, the transportation of water and dampness is out of order, and the transmission of fluid is impaired, so it is easy to generate water and dampness internally. Patients may have symptoms such as fullness (stomach distension and discomfort), loose stools (thin and unformed feces), drowsiness, dullness (lack of appetite and reduced food intake), and slippery tongue coating. When there are abnormalities in the body, it is recommended to seek medical advice from a medical professional.