Welcome to HCM
Any chest pain
and tightness should not be ignored as there is breathing problem also so first you should visit hospital/ER and get a urgent ECG and if it is normal then physical examination may indicate he has a lung pathology like Asthma
A complete workup with CBC, A X ray
chest and PFT ( Pulmonary Function Test) will be help ful to know the exact cause of his discomfort.
Once proper diagnosis is made treatment will be easy.
There is one more very important aspect is by chance if he is smoking
he must stop it as it is very harmful for both heart and Lungs.
Please take care
Good Luck .