Pleural thickening after six months of lung adenocarcinoma surgery can be treated with observation without treatment, anti-inflammatory treatment, surgical treatment, anti-tumor drug treatment and so on depending on the cause of disease. Causes of pleural thickening half a year after lung adenocarcinoma surgery include pleural thickening caused by pleurisy, thickening caused by pleural metastasis of lung cancer and so on. 1. Patients with no symptoms of pleural thickening caused by chronic pleurisy can be observed regularly without special treatment. 2. Patients with pleural thickening caused by acute pleurisy with obvious symptoms such as chest pain and fever usually need to be given antibiotic anti-inflammatory treatment. For patients whose pleural thickening is more extensive and causes respiratory difficulty, they need to be treated with pleurodesis if necessary. 3. For pleural thickening caused by pleural metastasis of lung adenocarcinoma, chemotherapy, targeted drugs, immunotherapy and other drug treatments are usually chosen. Once pleural thickening occurs after lung adenocarcinoma surgery, it is recommended to go to hospital for diagnosis and treatment by professional doctors.