Should i be concerned if my son just had a pulmonary function test, it came back abnormalpointing to emphysema./ bronchitis..how?

Yes: Your son is young, obviously. Abnormal pfts? Should be checked by an educated pulmonologist.

No smoking: If smoking stop. If no smoking needs blood test for Alpha one antitrypsin testing. Defeciency of this is associated with emphysema. A pulmonary evaluation may ALS be helpful in deciding what the pft means and to evaluate for adult onset asthma.

Additional tests: There may be an underlying cause for his airflow obstruction. I would suggest testing to include albuterol to document response. In addition, your physician may order a chest radiograph and alpha 1 antitrypsin level.