As we age, the smooth surfaces of the cartilage that line the bones of the shoulder joint begin to wear out and become larger, causing osteoarthritis – mainly caused by overuse. This is most common in people over the age of 50.
Symptoms include:

• Joint pain
• Tenderness
• Stiffness

This is an autoimmune disease causing one or more joints to become inflamed, and may affect both shoulders at the same time. Rheumatoid Arthritis can cause your shoulder bones to erode and become deformed over time.
Symptoms include:

• Tenderness and warmth in the joints
• Shoulder stiffness, especially in the morning
• Fatigue, weight loss or fever

When blood cannot reach the long bone in your upper arm (humerus), the cells in your shoulder bone begin to die and subsequently destroys the joint tissue in the shoulder. This is a progressive disease and gradually worsens over time. Avascular necrosis can happen due to shoulder dislocations, fractures or high doses of steroids or alcohol abuse.

Shoulder injuries such as fractures and shoulder dislocations may eventually lead to post-traumatic arthritis, which causes fluid to build up in the shoulder joint, resulting in pain and swelling.

Generally, a rip in the tendons of the rotator cuff causes this form of arthritis to develop.
Symptoms include:

• Intense pain
• Muscle weakness that can make lifting difficult