Symptoms of thyroid cancer lung metastasis mainly include cough, hemoptysis, dyspnea and other symptoms. 1. Cough: when thyroid cancer metastasizes to the lungs, cough may be the earliest symptom, and patients mainly have irritating dry cough with little or no sputum, and some patients may have increased sputum, which is usually caused by infection. 2. Hemoptysis: if thyroid cancer patients have lung metastasis, persistent blood in sputum or hemoptysis may occur if the tumor grows into the lumen. 3. Difficulty in breathing: further growth of the tumor may cause patients to have difficulty in breathing, which is mainly manifested as chest tightness, chest pain, shortness of breath and so on. Thyroid cancer lung metastasis not only has symptoms related to lungs, but also has symptoms related to hoarseness, difficulty in swallowing, etc. It is suggested that patients should take active treatment.