Thanks for the query
The description you have provided can be originating from following organs
The stomach: caused by conditions like peptic ulcer
, acidity or gastritis the pain feels under sternum and on the back
The hepatobiliary system
including gall bladder
, liver and common bile duct. caused by conditions like cholecystititis means inflammation of gall bladder due to stones or without stones and hepatitis of any type. Liver function test will help in evaluation
Sometimes hydatid cyst
also cause such symptoms which can be diagnosed by ultrasound.
It is recommended to have a visit to your doctor for proper evaluation.