Hi welcome to HCM... Here your father is suffering from chronic obstructive pulmonary disease ... So for that pulmonary function test by spirometry needs to be done .... It will diagnose case as well as detect severity which guides in treatment . You might needs bronchodilator therapy ... Your voice getting affected . So larynx has to be examined by indirect laryngoscopy examination.... If growth seen biopsy taken . If seems inflamned short course steroid and antibiotic given.... Avoid smoking and excess dust exposure . Consult pulmonologist with keeping this in mind. Take care ...