Cancer patients cause pain in the majority of cases, especially when it develops to the middle and late stages, and the degree of this pain will continue to increase as the disease progresses, causing great pain to the patient. After all, cancer is an invasive growth that can destroy the surrounding normal tissues. There are many nerves in the human body, and often the metastasis of cancer will cause a kind of tissue reaction and pain in the body when it invades the area and destroys the tissues, especially when it invades the nerves. But there are some extreme cases, some cancers do not show obvious pain. First of all, it must be very early stage, not destroying the surrounding nerves and not causing the body to be alerted. For example, a well-differentiated papillary thyroid cancer may be stable in the thyroid gland for a long time and does not show obvious growth behavior. However, the majority of these cancers will definitely cause pain when they reach a certain level of development.