The left side of the neck hurts when you press the inside. Usually, it is considered that the pain sensation is caused by trauma, infectious diseases, skin diseases and other factors. 1. Trauma: patients suffer from cervical spine muscle nerve damage due to irregular sleeping posture, external force squeezing the nerves, excessive turning of the head and keeping a posture for a long time. 2. Infectious diseases: when the body is infected by viral infections, such as viral colds, local tissue infections and other reasons, may lead to lymph node enlargement, which may lead to the patient’s neck on the left side of the inside of the pain symptoms. 3. Skin diseases: Often poor hygiene can lead to invasion of the skin by bacteria, fungi or other microorganisms, resulting in boils that are painful and especially noticeable when pressed. Other causes may also lead to pain on the left side of the neck when pressed inside, it is recommended that the patient consult a doctor in time to identify the cause, and then under the guidance of the doctor for appropriate treatment.