Causes for Halitosis:

• Most commonly, bad breath is caused by the bacteria in the mouth, which is breaking down any bits of food you haven't been able to brush, floss and/or wash away, or if your dentures haven't been cleaned properly. Hygiene is very important.
• Strongly flavored foods, such as onion, garlic, fish, cheese, meat and curry, can cause bad odors (these odors will usually released through sweat too).
• Consuming alcohol and smoking cigarettes can also have an effect on your breath, as well as stain your teeth.
• Bad breath can result from an infection or an illness, or some medication that you take. Persistent bad breath is usually related to gum disease (or warn you that you have one, so better to check with the dentist!).
• Other dental issues that can result in Halitosis include ill-fitted dental appliance, yeast infection of the mouth and dental caries.
• Extrostomia (medical condition dry mouth, can be caused by continuous breathing through the mouth, side effects of medication and salivary gland problems) can also impact your breath as saliva is crucial to moist and cleanse the mouth by neutralizing acids produced by plaque and washing away dead cells that accumulate on the tongue, gums, and cheeks.
• Other diseases and infections that might cause bad breath are as follows: pneumonia or bronchitis, chronic sinus infections, postnatal drip, diabetes, chronic acid reflux and liver or kidney problems.