Sudden improvement in patients with advanced lung cancer is often a sign that the treatment is effective and their physical state is improving. Not all patients with advanced lung cancer will necessarily experience progressive aggravation of their condition. Some patients with advanced lung cancer can receive active anti-cancer treatment, such as chemotherapy, radiotherapy, targeted therapy, immunotherapy, Chinese medicine and traditional Chinese medicine, etc., which can reduce the size of cancer foci, slow down the proliferation and growth of cancer cells, reduce the consumption of the body, and increase the appetite and improve the nutritional status of the patients, so their condition can suddenly improve, which is a good phenomenon. It is necessary to continue to use the current treatment plan for follow-up maintenance treatment, so as to maintain the condition in a stable or further improved state, which is conducive to prolonging the patient’s survival time.