Ulcers on the left side of the tongue are a clinical symptom of the oral mucosa, for which there are three general conditions that are more common in clinical practice. The first is the most common commonly known as oral ulcers, just located on the left side of the tongue, this ulcer is also called recurrent oral ulcers, oral aphthous ulcers, it is typically characterized by significant pain, and will be self-limiting and recurrent, this ulcer is generally not special intervention, in about 1-2 weeks time will also heal naturally, but this ulcer is also very difficult to eradicate, often in other parts of the They often occur again in other areas. The second common type of ulcer is the traumatic ulcer, on the left side of the tongue, which is generally associated with the sharpness of the tooth tip on the lingual side of the tooth, and which is relatively slow to heal because of the stimulation of the tooth tip. At the same time, if this kind of ulcer exists for a long time, it may become the third kind of cancerous ulcer. Cancerous ulcer means that the ulcer itself has undergone pathological changes and appeared malignant tumor, so it is necessary to consult a doctor as soon as possible to treat oral cancer.