Pain below the clavicle may be caused by functional pain after strenuous exercise, or it may be related to pathological factors such as costochondritis and lymph node swelling. 1. Strenuous exercise: after strenuous sports, such as strength training of the pectoral muscles, resulting in muscle fiber damage and soft tissue edema, can cause local pain. It is a normal physiological phenomenon and can be relieved by resting for a few days. 2. Costal chondritis: most of them are caused by trauma or infection, which can cause pain and swelling of the front chest wall, among which the pain in the 2nd rib cartilage is the most common. 3. Enlarged lymph nodes: Because of infection, tuberculosis and other factors, lymph nodes can be enlarged and pain below the clavicle can occur. There may be other causes of subclavian pain, and it is recommended that patients consult the hospital in time for examination and standardized treatment after clarifying the cause of the disease.