It is an inflammation of the gums that can progress to affect the bone that surrounds and supports your teeth. It is caused by the bacteria in plaque, a sticky, colorless film that constantly forms on your teeth. Plaque hardens (calculus) over time which harbors bacteria and infects the gums. In early stages, this is called Gingivitis. This often causes red swollen gums that bleed upon brushing and leaves an unpleasant taste in your mouth.
Gingivitis, if untreated, progresses to Periodontitis. This is a much more serious disease causing painful chewing, loose or shifting teeth and gum recession. Periodontal pockets form around the teeth where the bacteria have attacked the tissue and bone. Without intervention, the infection becomes more severe and the pockets deepen, resulting in tooth loss.