There are many causes for bad breath; some common causes are listed below.
- Food: Food is a primary source of bad odors that come from the mouth. Some foods, such as garlic, onions, spicy foods, exotic spices (such as curry), some cheeses, fish, and acidic beverages such as coffee can leave a lingering smell. Most of the time the odor is short lived. Other foods may get stuck in the teeth, promoting the growth of bacteria, which causes bad breath odor.
- Tobacco products: Smoking and chewing tobacco can leave chemicals that remain in the mouth. Smoking can also precipitate other bad-breath causes such as gum disease or oral cancers.
- Health problems: Sinus infections, pneumonia, sore throat (pharyngitis) and other throat infections, tonsil stones (tonsilloliths), thrush, bronchitis, postnasal drip, diabetes, acid reflux, lactose intolerance, other stomach problems, and some liver diseases or kidney diseases may be associated with bad breath.
- Dry mouth: dry mouth can also cause bad breath. Saliva helps moisten and cleanse the mouth, and when the body does not product enough saliva, bad breath may result
- Mouth infections: Cavities, gum disease, or impacted teeth may cause bad breath.
- Dentures or braces: Food particles not properly cleaned from appliances such as braces can rot or cause bacteria and odor. Loose-fitting dentures may cause sores or infections in the mouth, which can cause bad breath.
- “Morning breath”: Bad breath in the morning is very common. Saliva production nearly stops during sleep, allowing bacteria to grow, causing bad breath.
- Pregnancy: Being pregnant in itself does not cause bad breath, but the nausea and morning sickness common during pregnancy may cause bad breath. In addition, hormonal changes, dehydration, and eating different foods due to cravings may also contribute to bad breath during pregnancy.
- Other causes of bad breath: Objects stuck in the nose (usually in children), alcoholism, and large doses of vitamin supplements may also cause bad breath.