My chest hurts when I breathe (near the heart) and if I stretch my back hurts. Is it serious?

The symptoms reported are relatively common, and are accompanied by numerous tables, mostly banal (like flu, colds, sprains ...) and tend to resolve themselves or analgesia. However, they can sometimes be manifestations of more serious but rare diseases, so without a physical exam I can not be more concise about the severity of symptoms. If symptoms are isolated, without fever or other signs of infection, without respiratory distress or cough or sputum brownish ... In short, no other warning signs that can guide a potentially serious process, and are of short duration (less than one week), it's likely to be a self-limiting process without importance.