There are many reasons for neck swelling, mainly for the following aspects: 1, sebaceous cysts, this is due to the skin follicle obstruction, the dander and oil can not be discharged, resulting in more and more large, resistance to low or local extrusion will cause the wall of the cyst to rupture, redness, swelling, pain, and enlargement. 2, enlarged lymph nodes, often due to bacterial or viral infections, a small number of blood system diseases, or even malignant tumor lymph node metastasis and so on. 3, lipoma, this is due to the increase in fat particles caused by, obese people. The lymph node enlargement is often caused by bacterial or viral infection, and a small part of it is caused by hematological diseases, even malignant tumors with lymph node metastasis, etc. Lipoma is caused by the enlargement of fat particles, and it is common among obese people.4 Thyroid diseases, such as nodular goiter and thyroid tumors are common, which are related to diet and heredity, etc.5 Metachronous cysts are also related to thyroid bone cysts. In short, if you find a swelling in the neck, you need to go to the hospital in time in order to clarify the cause of the disease.