Hi,
Thanks for asking the query,
Bad breath can be because of several reasons,
Poor oral hygiene , deposition of plague and calculus, periodontal infections , tongue coating ,
xerostomia, faulty restorations retaining food and bacteria , oral pathologic conditions , mouth breathing habit , use of certain medications fasting ,
starvation , foods like garlic , onion
Diseases of GIT, GERD ,Nasal infections like rhinitis ,
Pulmonary infections like
bronchitis
Systemic conditions like
diabetes ,
dehydration, fever.
I would suggest you to get a complete checkup done.
Visit to a
Dentist , get complete mouth scaling and polishing done .
use
chlorhexidine mouthwash gargles twice daily .
Drink lots of water.
Maintain a good oral hygiene .
Hope this helps out.
Regards....