There are several reasons for clavicle enlargement: external impact, sternoclavicular arthritis, tumor. It is recommended to go to the hospital to do ct examination to clarify the cause of the disease and then do targeted treatment. 1. External impact: the clavicle may suffer from external impact, which may lead to local soft tissue edema or clavicle fracture, such as touching the clavicle part with local displacement activities, or local swelling and subcutaneous bruising or even bone friction sound, then the clavicle fracture may occur. 2. Sternoclavicular arthritis: it may lead to protrusion of the sternoclavicular joint of the patient, which is mostly found in women, and localized redness, swelling and pain may occur. Diclofenac diethylamide emulsion, aspirin and other drugs can be taken for pain relief and anti-inflammatory treatment. 3. Tumor: Osteoma or soft tissue tumor in the clavicle area may also lead to clavicle enlargement and protrusion. Ultrasound and CT examination of the clavicle area can be done, and further examination and diagnosis will be needed if abnormal hyperplasia or occupying lesions are found. The cause of clavicle enlargement is complicated, it is recommended to go to the hospital immediately for diagnosis and symptomatic treatment under the guidance of professional doctors, and not to blindly use medication or treatment by oneself to avoid delaying and aggravating the condition.