A bulging clavicular fossa in the neck can be related to trauma, subcutaneous masses, and pneumothorax. Subcutaneous masses in the clavicular fossa area such as lipomas, fibromas, and sebaceous cysts may also appear to bulge when the tumor is large. Trauma may result in clavicle fracture, and bleeding from the broken end of the fracture will cause obvious swelling in the clavicle fossa area, which may be accompanied by severe pain, limited shoulder joint movement, and subcutaneous bruising. In the case of pneumothorax, the gas reaches the subcutaneous area of the clavicular fossa, and the bulging symptom will also appear. If the neck clavicular fossa bulging suggests that the patient to go to the hospital to improve the examination, clear the cause of the disease, receive regular treatment.