This is a very common problem. There are multiple reasons for bad breath- 1)can be due to plaque and calculus deposited on the tooth- get professional cleaning of the teeth and use mouth wash twice a day. 2)Bacteria on the tounge- clean your tounge twice a day, either with a tounge cleaner or bristles of brush 3) GERD- visit gastroenterologist.

its because of deposits..so go for scaling done and do mouth wash rinses.

Go for scaling twice a year and use mouthwash twice a day. Brush properly two times daily

Go to a dental clinic & do proper cleaning of ur teeth,  do gargling with clohex plus mouthwash twice a day for 10 day,  but for further treatment u have to visit a dental clinic.