Lymph node pain under left jaw may be caused by lymphadenitis, acute tonsillitis, enlarged lymph nodes and so on. 1. Lymphadenitis: If the pathogenic bacteria invade from the skin, mucous membrane or nearby infectious lesions, it leads to pain in the lymph nodes under the left jaw of the patient, accompanied by enlargement, fatigue, fever and other uncomfortable symptoms. 2. Acute tonsillitis: when the patient’s body resistance declines, the pathogenic bacteria will multiply, the toxin destroys the crypt epithelium, the pathogenic bacteria invade the tonsil parenchyma, triggering the pain in the lymph nodes under the left jaw, and the patient will have severe sore throat, accompanied by swallowing pain, and the pain will be radiated to the ear. 3. Enlargement of lymph nodes:If infected bacteria, fungi and other inflammatory reactions, resulting in increased lymph node volume, resulting in lymph node pain under the left jaw, and some patients are accompanied by fever, fatigue and other symptoms. It is recommended that patients go to the hospital in time, under the diagnosis of the doctor, according to the patient’s specific condition, to take targeted treatment, so as not to cause adverse effects on the body.