Lung cancer refers to a condition where, due to genetic mutations in human cells, cells grow disorderly or wildly, forming a solid mass-like lesion primarily known as lung cancer. Due to the uneven growth of lung cancer, local necrosis can occur, leading to bleeding, making coughing up blood a very common clinical manifestation in lung cancer. The severity of coughing up blood is classified into mild, moderate, and severe. Generally, if a single instance of coughing up blood is less than five milliliters, it can be managed with Yunnan Baiyao. However, if the amount exceeds 100 milliliters, it is advisable to seek medical attention promptly to prevent life-threatening risks from massive hemoptysis. (The use of medications should be under the guidance of a doctor.)