Thank you for the query.Chest discomfort
can be caused by acid reflux
disease indeed. This condition is very often associated with asthma. This disease can be responsible for your other symptoms, especially chest tightness
, phlegm. Coughing is very characteristic for asthma. Physical activity can make this condition worse and trigger phlegm secretion.
Chest pain while lifting can be also caused by spine problems or muscles problems.
I suggest you to visit pulmunologist and have blow test (spirometry
done). You should also consult orthopedist and consider spine MRI.
Hope this will help.