Lymph node pain in the jaw is commonly caused by the following: First, parotitis, when the parotid gland is infected, it can lead to swelling and pain in the surrounding lymph nodes, which requires ultrasound and blood tests of the parotid gland. Second, submandibular adenitis, which is caused by infection of the submandibular gland, which can be either viral or bacterial, and requires ultrasound and C-reactive protein and blood tests of the relevant parts for diagnosis. Third, dental infections, such as wisdom tooth infection, which requires a dental film and ultrasound in the Department of Dentistry or Maxillofacial Surgery to clarify, if the disease, dental treatment or tooth extraction. Fourth, there are other reasons, such as thyroid disease can also lead to swollen and painful lymph nodes in the jaw, which need to go to general surgery or head and neck surgery to check thyroid ultrasound and lymph node ultrasound, and if necessary, perform lymph node biopsy to clarify its nature. In conclusion, if lymph node pain in the jaw persists, you need to go to the hospital promptly to clarify the cause.