hello Bad smell can be because of 1. Poor dental hygiene 2. Nasal discharge and infection 3. Reflux disease and constipation. For poor dental hygiene you must brush daily and keep your mouth clean by doing gargles with Betadine gargles 2 tsf in half glass of water 2 times a day. For nasal discharge and nasal crusting you must be aware you have it or not. if yes then take medicines after getting examined by ENT specialist with nasal normal saline sprays. If you have reflux then take--- Tab. Mucinac 600 once daily Tab. Omeprazole +Domperidom two times a day half an hour before meals Syp. antacid gel 2 tsf two times a day half an hour before meals multivitamin twice daily Keep head end of bed elevated. Avoid alcohol, Smoking Do brisk walking daily Go for walk after dinner Avoid spicy food Avoid late night coffee follow up after 7 days. and for constipation eat salads and fresh fruits or you can take isabgol husk daily with milk.