Thank you for the query.
As such symptoms appear it is advisable to rule heart and lungs diseases at first. You should have at least ECG, chest X-ray performed and spirometry
(especially if you smoke) performed.
If you find this tests normal, gastric diseases should be ruled out. Such symptoms may be caused by peptic ulcer
, gastric reflux
(this one is often associated with asthma - spirometry will rule asthma out) ,gall stones
, pancreas diseases. So you should have endoscopy performed, full blood work with pancreas and liver enzymes and urine tests.
Hope this will help.