There are number of causes for rib cage pain like heart disease
, Pleural Effusion
or infection, Abdominal discomfort and muscular spasm. You need to be investigated properly and get to a diagnosis. There is a battery of test to be preformed. But to be cost effective I need some more detail:
1. What factors increases your pain?
2. Is pain associated with shortness of breath
3. Your age and weight?
4. Any history of cough and fever?
5. Any digestive system problem like constipation
The upper chest pain can be due to Cervical spondylosis
as it get revealed by posture change.
Give answer to the queries so that I can give you a proper detailed answer.