Nodular abnormal signal enlarged lymph nodes in the left submandibular gland area are usually related to pharyngeal inflammation, tonsillitis, odontogenic infection and other factors. 1. Pharyngeal inflammation: for example, pharyngitis, pharyngolaryngitis, etc., after being stimulated by inflammation, it is easy to lead to the formation of nodules in the left submandibular gland area, and abnormal signals of nodules can be found through examination. 2. Tonsillitis: repeated inflammation of the tonsils can easily cause tonsillar abscess and tonsillar enlargement, and when the symptoms are severe, they will radiate to the left side of the jaw and the hypoglossal area, thus forming abnormal nodule signals. 3. Odontogenic infection: for example, gingivitis, periodontitis, apical abscess, etc., may repeatedly stimulate the left submandibular gland area, resulting in localized lymph nodes, which will show abnormal signals through examination. In addition to the above factors, the nodular abnormal signal in the left submandibular gland area may also be caused by enlarged submandibular lymph nodes, submandibular gap infection, etc. It is recommended to analyze the cause of the disease together with the routine blood test and then carry out the treatment.