Back pain in advanced thyroid cancer stage needs to identify the cause of the disease, and then symptomatic or radical treatment should be carried out according to the cause of the disease. Lower back pain in advanced thyroid cancer may be caused by trauma, lumbar muscle strain, metastasis, etc. It is necessary to find out the cause of the disease and treat it in time. 1. Trauma: when the back is hit and caused by trauma, it will lead to lumbar pain. At this time, it is necessary to check whether there is any organ injury or fracture, etc. If there is serious injury, it is necessary to consider surgery; if there is no serious injury, it is possible to take more rest and have conservative treatment. 2. Lumbar muscle strain: long-term labor or high-intensity exercise can cause lumbar muscle strain triggered by low back pain, to identify the cause of the disease can be taken after the brake rest, massage, physiotherapy and other measures to reduce the symptoms. 3. Metastasis: advanced thyroid cancer tumors can metastasize to the bones, invade and compress the surrounding nerves and tissues, which may also cause low back pain. Combined with CT, MRI, PET-CT and other examinations, it can help to diagnose and identify, and then choose the appropriate treatment according to the condition. There are many causes of advanced thyroid cancer that can cause back pain, if you have any discomfort in this regard, please go to the hospital in time.