The most common type of arthritis, is when the cartilage protecting the joints degenerates or wears down. The chronic pain caused by osteoarthritis is often worse at night. The affected joints might creak or click due to the loss of cushioning from the cartilage. In addition to stiffness and weakness, the joint might appear swollen. Osteoarthritis most often occurs in people over 50 and can be hereditary. 

The group of for muscles and tendons that connect the arm to the shoulder is called the rotator cuff. The tendons are susceptible to inflammation and bruising, leading to pain when performing overhead activities, sleeping on the affected side or reaching behind your back. Left untreated, rotator cuff injuries can cause persistent shoulder pain even Frozen Shoulder. 

Frozen shoulder, or adhesive capsulitis occurs when the capsule of connective tissue that is the lining of the shoulder joint thickens and becomes inflamed. Frozen shoulder is different from conditions such as bursitis because the pain and stiffness occur when the shoulder is at rest. Frozen shoulder is more common in women over age 50 and those with diabetes or thyroid disease, but the cause of the problem is unknown. "It can be a result of trauma or injury, but many times there is no precipitating factor that can be identified."