Pain in upper top stomach under right breast when breathe in and out and a full feeling what could this be?

See your doctor: Your symptoms may be signs of something significantly wrong. One cannot tell without a complete history, physical and possible lab/imaging tests. Follow with your doctor as soon as you can. Things that can cause pains in chest and ribcage include heartburn, pneumonia, gallbladder problems, shingles, infectious processes, liver disease, kidney problems, heart attacks, or blood clots.

See an osteopath: Your symptoms warrant seeing an osteopathic physician for evaluation and treatment. When you describe that you feel it more when you're breathing in and out, means that it may be related to your ribs, or of musculoskeletal origin. However this can only be determined by physical examination. S/he will take a detailed medical/trauma history to determine exactly what is causing this ; provide tx.

Costal;pleural: Costochondritis may be caused by trauma, such as bumping the rib cage; as a result of a viral infection; or as part of an inflammatory disease process. Usually the cause is unknown; pleurisy is inflammation of the lining of the lungs and chest (the pleura) that leads to chest pain (usually sharp) when you take a breath or cough.