Your collarbone, or clavicle, runs horizontally across the top of your chest just below the neck and out to the shoulder. You should be able to feel it easily with your fingers. Because of the collarbone's position and prominence, it takes a lot of pressure when weightlifting. If you feel pain in the collarbone after lifting weights, you may have damaged the bone. If the pain is serious, consult a doctor as soon as you can.
The condition sometimes called weightlifter's shoulder is medically known as a distal clavicular osteolysis. This occurs when, over time, your collarbone develops lots of tiny stress fractures through regular lifting of heavy weights. According to the Orthopod website, osteolysis occurs when the small pieces of bone are absorbed into the body, causing the area to deteriorate. Symptoms include a throbbing pain near your shoulder after lifting weights or during the course of the day.
Sternoclavicular Joint Separation
If you lift heavy weights or suddenly increase your load, you could suffer from sternoclavicular joint separation. This is where ligaments attaching the collarbone to the sternum become torn or separated, according to the University of Sports Medicine. Though more often associated with falls or impact, heavy pressure on the collarbone can trigger the condition. You'll feel sharp pain at the top of your chest in the area where your collarbone meets your breastbone. Speak to your doctor, who may prescribe painkillers and recommend rest, ice treatment and possibly a sling for several weeks.
Strains to the muscles or ligaments in your shoulder or neck can cause pain in and around the collarbone. Muscle strains result from putting too much pressure on the region, a common result of heavy weightlifting. Resting for a few days should be enough to relieve the pain and repair the muscle. Ligament strains may take longer to heal, with small rips or tears in the tissue that make it painful to lift weights or move freely.
Possibly the most serious reason for pain after lifting weights is a potential collarbone fracture. You will experience sharp and lasting pain around the broken section of your clavicle if you suffer a fracture. It's unlikely that you'll break a collarbone from normal weightlifting with good technique and comfortable weight sizes. However, if you drop a barbell, lift a weight beyond your ability or fall when lifting, you could break your collarbone. The broken region will hurt to touch and may even stick out noticeably under your skin. If you suspect a fracture, visit an emergency room as soon as possible for an x-ray.