Bad breath (also called mouth odour) is usually caused by simple everyday issues, but sometimes it can also point to an underlying health problem. The most common cause is poor oral hygiene, where food particles and bacteria remain in the mouth, especially on the tongue and between teeth. Other causes include tooth decay, gum infections, dry mouth (less saliva), strong-smelling foods like garlic and onion, smoking or tobacco use, not drinking enough water, and sometimes stomach issues like acidity or indigestion. In some cases, sinus infections, tonsil problems, or uncontrolled diabetes can also contribute. To maintain fresh breath, the most important step is good oral care; brush your teeth twice daily, clean your tongue gently every day, and floss to remove trapped food. Drinking enough water keeps the mouth moist and reduces bacterial growth. Rinsing your mouth after meals, using a mild mouthwash if needed, and chewing sugar-free gum can also help keep breath fresh. Avoiding smoking, tobacco, and excessive coffee or alcohol makes a big difference. Eating fibre-rich fruits like apples and guava can naturally clean the mouth and increase saliva. If bad breath continues despite good hygiene, or if there is tooth pain, bleeding gums, or a persistent sour taste, it is important to visit a dentist or doctor to check for dental or medical causes. With regular care and attention, most cases of bad breath can be easily controlled and prevented.