As per CT report his 50%lungs are affected. Non smoker , lungs affected due to working in chemical fumes environment of leather factory. Cold weather affects a lot , hence brought here in Pune. Currently on oxygen therapy at home. Oxygen saturation 73-74. Still having breathlessness and easily catch cough and could even in Pune. Pls suggest what to do to increase his immunity and reduce breathlessness. Medicines : medrol 4mg and nebuliser duolin and livolin apart from BP medicine's.