The common clinical causes of pain below the left ear include mumps, inflammation of the pharynx, and skin infection under the left ear. 1. Mumps: this disease refers to a respiratory infectious disease caused by the mumps virus, which is mostly seen in children and adolescents, the main clinical features of the parotid gland non-purulent swelling, pain, etc., with the earlobe as the center of the gradual development of the forward, backward and downward. 2. Inflammation of the pharynx: clinically common such diseases are acute tonsillitis, acute pharyngolaryngitis, etc., which will cause inflammation of the lymph nodes in the angle of the mandible and pain symptoms, this kind of pain will be radiated to the area under the ear when the people suffering from the disease do the swallowing action, with the clinical manifestations of pain in swallowing, a foreign body sensation of swallowing and fever. 3. Skin infection under the left ear: clinically common such diseases are folliculitis, sebaceous cysts secondary infection, etc., which may cause pain in the local skin under the left ear. It is also accompanied by redness, swelling, pain and pressure. It is recommended to pay attention to the daily diet to keep light, avoid eating spicy and stimulating food, the appearance of pain under the left ear, it is recommended that the hospital consultation, diagnosis and treatment.