Shoulder pain means the physical discomfort of the shoulder, including the joint itself or the muscles, tendons and ligaments that support the joint.The shoulder has a wide and versatile range of motion. When something goes wrong with your shoulder, it hampers your ability to move freely and can cause a great pain and discomfort.
You can injure your shoulder by performing manual labor, playing sports, or even by repetitive movement. Certain diseases can bring about pain that travels to the shoulder. These include diseases of the cervical spine (neck), as well as liver, heart, or gallbladder disease.
This is a condition characterized by swollen tendons. Another common cause of shoulder pain is impingement syndrome where the rotator cuff gets caught between the acromium (part of the scapula that covers the ball) and humeral head (the ball portion of the humerus).

Causes & Treatment of shoulder pain:
Causes:

Arthritis ,torn cartilage,torn rotator cuff,swollen bursa sacs or endons,bone spurs (bony projections that develop along the edges of bones),pinched nerve in the neck or shoulder,broken shoulder or arm bone,frozen shoulder,dislocated shoulder,injury due to overuse or repetitive use,spinal cord injury,heart attack

Diagnosis & Treatment :
Diagnosis:

The Doctor may order specific test like X Ray, MRI, CT Scan,electrical studies,Arthogram and Arthoscopy to help identify the cause of your pain and any other problems.

Treatment:

Treatment will depend on the cause and severity of the shoulder pain. Some treatment options include physical or occupational therapy, a sling or shoulder immobilizer.