1)      Dietary – foods causing unusual smells like garlic, onion,

2)      Smoker’s breath

3)      Poor oral hygiene

4)      Persistent mouth breathing

5)      Tonsillitis – tonsillar crypts may contain food particles

6)      Acute ulcerative gingivitis

7)      Chronic periodontitis

8)      Infected tooth socket

9)      Pericoronitis

10)    Sinusitis chronic

11)    Bronchiectasis

12)    Lung abscess

13)    Pharyngeal pouch

14)    Esophageal diverticula

15)    Rumination syndrome