Unpleasant odor from the breath
Poor Dental Hygiene
Some foods such as onions and garlic
Crash dieting, fasting, and low-carbohydrate diet
Certain medications
Smoking
Dry Mouth Syndrome
Periodontitis
Infections or inflammation in the nose, throat, or sinuses
Liver and other types of cancers, liver failure, and other metabolic diseases
Gastroenterologist
ENT (Otolaryngologist)
Dentist