Pressure and pain on the left side of the throat may be caused by acute tonsillitis, acute pharyngitis, lymphadenitis and other diseases. It is recommended to go to the hospital for consultation. 1. Acute tonsillitis: tonsillitis is an infectious disease caused by pathogenic microorganisms, the common causative organism is beta-hemolytic streptococcus, followed by viral infections, immune factors, acute inflammation of neighboring organs are also triggers of tonsillitis. Patients mainly manifested as sore throat, pain is obvious when swallowing, and pressure pain can also appear on the left side of the throat. 2. Acute pharyngitis: acute pharyngitis is an acute inflammation of the pharyngeal mucosa, submucosa and lymphatic tissues, and the etiology is related to microbial infections and environmental stimuli. Patients will have symptoms such as pharyngeal dryness, painful swallowing, etc. Some patients may have pressure pain, such as pressure pain on the left side of the throat. 3. Lymphadenitis: Lymphadenitis is a benign lesion of lymph nodes, which is mostly caused by bacterial and germs infection, and its primary focus may be a disease of the pharynx, which involves the inflammation of cervical lymph nodes. Typical symptoms are enlargement and pain in the lymph nodes, which can be characterized by pressure and pain on the left side of the throat. Painful pressure on the left side of the throat can also be seen in parapharyngeal space infections, submandibular space infections and other diseases. Once the above symptoms appear, it is recommended to go to the hospital as soon as possible for examination, clear diagnosis and standardized treatment as prescribed by the doctor.