Many patients have a feeling of tightness of breath after surgery, and because they do not understand the cause, many patients tend to worry that something is wrong with them, that they have inflammation, or that they have complications, causing unnecessary tension. In fact, many post-operative tightness of breath is a normal phenomenon. Studies have shown that after open-heart surgery, lung function will decline by at least about 30% due to pain and inflammatory response, even if no lung tissue is removed, and even more if there is removal of lung tissue. Recovery of lung function will gradually return to 80-90% within 3-4 months after surgery, and to complete full recovery of lung function will take about 6 months in most patients. For patients who have had lung tissue removed, 100% lung function may not be restored. Therefore, it is very normal for patients to feel tight after surgery compared to before surgery, and as long as the tightness is not very pronounced, there is no need to be particularly nervous.