can have many underlying reasons, one of them are digestive problems and more importantly COPD (Chronic Obstructive Pulmonary Disease
). I suggest you see a Pulmologist to get COPD treated. Also u must see a Gastroenterologist to treat your stomach ailments.
Also get yourself checked by Dentist
who will assess your oral hygiene
status, and do a scaling procedure if required.
I hope this will help. Thanks.