Gingivitis is a gum disease that causes red, swollen gums that bleed easily when brushed.

It is caused by the bacteria in plaque, which can irritate the gums. It can be prevented, treated, and reversed by brushing twice a day and flossing once a day. If gingivitis is not treated, the bacteria that cause it can affect the tissue and bone that support the teeth. This can lead to a more severe disease called periodontitis, which may lead to tooth loss.