How do i tell whether a shoulder injury is bursitis or rotator cuff tear? pain when lift arm up or sideways or bear weight. treatment method same?

Get examined: "bursitis" of the shoulder and a rotator cuff tear can present w/ very similar symptoms(pain w/ motion of shoulder away from body , night pain, etc).However subacromial bursitis will generally improve w/ time, rot.Cuff tears usually not. A simple physical exam by an ors in most cases will be give u your answer.Occ. A diagnostic injection will be needed as well.A high quality MRI is definitive. Gl!

You usually can't: A simple exam of the shoulder should be able to give you the answer. If conservative therapies fail, an MRI would be helpful.