Gum disease is the most common cause of bad breath. It has two forms, gingivitis (inflammation of the gums) and periodontitis (infection of the gums). Periodontitis is the more severe condition. It affects the structures that hold the tooth in its socket and so can result in tooth loss. It often occurs with little or no pain and we are only aware of it when it is at a late stage. Bad breath can help us to detect this disease early.
Everyone has bacteria living in their mouth. When there is an inflammation or infection in the mouth, these bacteria digest human cells and produce by-products called volatile sulphur compounds, which smell like bad eggs. These compounds are produced in everyone's mouth during the night. People with gum disease produce more.