The collarbone (or clavicle) is one of the most commonly fractured bones in the body, and a broken clavicle is the most common cause of clavicle pain. It is relatively easy to fracture the clavicle, and this occurs frequently in sports activities, especially with falls or in contact sports. If you have recently had an injury, then this is almost certainly what is going on. You should see your doctor
who can perform an x-ray
to confirm the diagnosis and can prescribe pain medication to help. Clavicle fractures typically do not need to be set, as they heal on their own except in the most severe cases.
Other causes of pain in the collarbone region include should injuries. For example, the joint that attaches the collarbone to the shoulder is called the acromioclavicular joint, and this joint can be sprained with a blow to the shoulder or other injury. Severe sprains of this joint are called "separated shoulder" and can require intervention from an orthopedic doctor.
Finally, inflammation of the acromioclavicular joint, in the absence of injury, is quite common, and tends to get better with anti inflammatory medications.
Start by seeing your primary care doctor
for some initial advice.