Hi! Welcome to Healthcaremagic. I read your query. Bad breath can be due to various reasons. Local causes like Improper oral hygiene, plaque and calculus, prolonged dry mouth, cavity and systemic diseases of lung,liver, gastrointestinal tract, kidney, diabetes, high starch diet, etc. Drink lots of fluid. Use sugarless gums. Brush twice daily and use mouthwash. Do not leave dry mouth for long duration. Rinse aftrr every time you eat and avoid acidic and spicy food and beverages. Visit a dentist and get oral prophylaxis done. If you have acidity and reflux problem, consult physician and take treatment as this also leads to bitter taste and smell. If the problem persists, i suggest you to see your physician and get furtger investigations done such as blood test done along with chest x-ray, KFT, LFT, urine test, etc. Hope the answer helps you. Thank you!