Tonsil stones are caused by the buildup of food particles in the tonsils, which promotes the growth of microorganisms that lead to the formation of the stones. Tonsil stones can be caused by poor oral hygiene or medication that dry out the mouth. Tonsil stones can also be developed in people with sinusitis and rhinitis. This is due to a buildup of mucus in the nose and throat. Fortunately, there are several ways to treat these conditions, including the use of prescription medications, oral hygiene techniques, and lifestyle modifications.