Sharp like stitch pain under ribs towards side feel more when sat and expand chest and arching back causes pain in area mimic pain when touch ok stood?

Chest Pain -See Doc?: When to see a doctor? How do you know when you need medical help for chest pain? It's not always easy to tell. Helpful simple quiz: http://edition.cnn.com/HEALTH/help.at.home/chest.pain/content.html

See your Doc: Chest pain can be a symptom of heart disease but may be may other things such as esophageal spasms, great vessel disease, respiratory disorders (asthma, COPD, bronchitis, infections), and muscle problems to name a few. It really depends on the clinical situation and other symptoms you may be having.