There are many reasons for chronic bad breath or halitosis. It may be more than that garlic toast, wine tasting or that fasting diet—it could be a medical problem. Most of the time bad breath does start in the mouth so the common diagnosis is food, smoking, drinking or dental problems. Dieters should also be aware that ketoacidosis, the breakdown of chemicals during fasting, also creates bad breath.
In addition, there are medical conditions that cause or contribute to bad breath.
Many other diseases and illnesses may cause bad breath. Here are some to be aware of: respiratory tract infections such as pneumonia, sinusitis, and lung, kidney or liver disease.
Conditions of the mouth, nose and throat can cause halitosis. Sometimes bad breath is associated with sinus infections because nasal discharge from the sinuses in the back of the throat. If a young child has bad breath, he/she may have a small object in his nose – like a bean or a small toy. A throat infection, bronchitis and upper respiratory infection in which the sufferer coughs up an odorous greenish or yellowish discharge can cause bad breath too. Periodontal disease is an infection of the mouth causing bad breath. Odor can also occur with chronic lung infection or a lung abscess.
Other systemic bad breath causes may be kidney or liver failure. A urine-like mouth odor can be caused by kidney failure while liver failure may cause an odor described as fishy. Gastro esophageal reflux disease (GERD) causes the chronic repeat (reflux) of stomach acids and this condition can be associated with bad breath.
Of course, beyond the infectious or systemic causes of halitosis, the food we eat can cause bad breath.