A bag at the back of the neck at the cervical vertebrae may be physiological causes such as fat accumulation, poor posture, etc., and may also be pathological causes, such as lipoma, carbuncle, etc.. ⒈ physiological reasons (1) fat accumulation: simple obesity will make excessive fat accumulation in the cervical spine, the back of the neck formed a similar package. (2) poor posture: the normal cervical spine is forward protruding, the thoracic spine is backward protruding, if the long-term low head to play cell phones, desk work and other poor posture, will make the cervical spine is too forward protruding, the thoracic spine is too protruding, the bony changes will also make the relevant muscle groups tense, swollen, resulting in muscle tissue hyperplasia, the back of the neck, cervical vertebrae at the formation of the mass. Peculiar pathologic causes (1) Lipoma: a bag at the back of the neck at the cervical vertebrae may also be caused by lipoma, lipoma consists of mature fat cells, belongs to a kind of slow-growing benign tumors, if the growth of the lipoma is too large, it may compress the surrounding nerves, and there is a sense of numbness and pain. (2) Carbuncle: It is a bacterial infectious skin disease, mostly caused by Staphylococcus aureus infection, which makes the adjacent hair follicles and surrounding tissues pus-filled and infected, resulting in a bag at the back of the neck at the cervical vertebrae, but accompanied by redness, swelling, heat and pain in the surrounding tissues and other symptoms. After excluding physiological reasons, you should go to the hospital in time to get a clear cause of the disease and then carry out targeted treatment.