I’m a student of TCM and a friend of mine told me about his old injury. More than 20 years ago he was hit by a car - his chest was inured. He recovered and had no problems with his health. The only thing that wonders him is his chest weakness that comes and goes accordingly to the weather. When he is tired and it’s windy, he experiences a slight discomfort in the right lung area and he his upper body strength is weaker. His lungs are ok, the wondering thing is the wind affecting his chest. How can it be understood in TCM theory?