Syndrome of the wei stage

The syndromes of the wei stage refers to pathological changes resulting from dysfunction of defensive qi due to invasion of the muscles and body surface by exogenous febrile pathogen. The wei system is the exterior defense of the human body and includes the skin and muscles on the body surface. As it functions to readjust body temperature and resist exogenous pathogenic factors, it is closely related to defensive qi and the lung. Invasion by pathogenic factors may result in pathological changes of the lung and defensive qi.

Principal clinical manifestations are fever, mild aversion to wind and cold, headache, cough, absence of sweating or slight mild thirst, swelling and pain of the throat, red tongue tip and borders, a thin and white tongue coating, and a superficial and rapid pulse.

This syndrome is often seen at the early stage of acute febrile diseases. The retention of febrile pathogen at the body surface binders defensive qi resulting in fever and slight aversion to wind and cold. Dysfunction of defensive qi in opening and closing the pores leads to either absence of or only slight sweating. Hindrance of defensive qi may also induce disturbance of the qi of the meridians, which may further cause headache. Furthermore, as the skin and body hair are related to the lung, hindrance of defensive qi may lead to dysfunction of the lung in dispersing, which manifests as coughing. The throat is the gateway of the lung, so invasion of the lung by febrile pathogen may give rise to swelling and pain of the throat. Slight thirst is a consequence of the consumption of body fluid by febrile pathogen. Red tongue borders and tip, thin and white tongue coating, and superficial and rapid pulse are signs of exterior heat.

The principle of treatment is to relieve the exterior syndromes with cool and pungent mild diaphoreses and to dissipate sweat through the wei system. The method of promoting lung qi in dispersing and descending is used in conjunction. If acupuncture is applied, points are mainly selected from the Lung Meridian, the Large Intestine Meridian, the Du Meridian and the Bladder Meridian.