After 25 days of lung adenocarcinoma surgery, back pain when lying down in bed is firstly considered after clarifying the pathological stage, which may be caused by surgical injury, inflammation stimulation, invasion of lung cancer to pleura on the back, and so on. 1. The intercostal nerve is damaged during lung adenocarcinoma surgery, which leads to back pain when lying down after surgery, and some patients need to take acetaminophen and other medicines to alleviate the pain. 2. Inflammatory pain caused by bacteria and other pathogenic bacteria invading the lungs, due to the low immunity of lung adenocarcinoma patients after surgery, it is easy to be infected, thus causing back pain, usually need to give sensitive antibiotics to control the infection and reduce the pain. 3. Lung adenocarcinoma cancer cells invade the pleura of the back and cause pain. As the stage of lung adenocarcinoma is late and the surgery is not radical resection of lung adenocarcinoma, the residual cancer tissues in the body invade the pleura and cause pain, so it is usually necessary to give strong opioids such as morphine to relieve pain, and at the same time, according to the condition of the patient, give anti-tumor treatments such as targeting and chemotherapy to reduce the pain. In either case, it is recommended to consult a doctor and standardize the treatment.