"My shoulder and arm hurt at NIGHT!". Why is this? Night pain is one of the most common symptoms of a shoulder problem. This problem can be something minor such as bursitis or tendonitis...or it could be more problematic such as a rotator cuff tear or arthritis. There are a few reasons why pain seems to be worse at night. First...during the daytime most people are so active and on the go that they simply don't have the time or energy to focus on pain in the shoulder. How