Your tonsils are made up of lymphatic tissue that is covered in pink mucosa. Nooks and crevices called the tonsillar crypts cover the surface of the tonsils; these crypts can become clogged with foreign materials such as dead cells, bacteria, and food particles, especially in those who have large tonsils in relation to their throat diameter, such as children and adolescents. If this accumulated material is not removed quickly, it can become concentrated and harden into pale, irritating tonsil stones.

Tonsil-stone formation is closely associated with the size and depth of a person's tonsillar crypts. For example, individuals who suffer from chronic inflammation of their tonsils (known as tonsillitis) are the most likely to develop tonsil stones. Researchers suspect that this is related to the tonsils' increased size and the infection's exacerbation of the tonsillar crypts.

Although not all people with tonsil stones experience symptoms, the formation of tonsil stones is also associated with discomfort and bad breath in some cases. According to a study from 2007 at the State University of Campinas in Brazil, tonsil stones were observed in 75% of tonsillitis patients who complained of bad breath, as opposed to 6% of patients with normal breath. Most individuals with tonsil stones, however, may not experience noticeable symptoms, and therefore may only discover their condition once several stones become dislodged in their mouth.

Although many people develop small tonsil stones frequently, only a few patients have large and fully hardened tonsil stones. If you suspect you may be experiencing tonsil stones or that your tonsils may be enlarged and at risk for further issues, see your doctor. He or she can conduct a physical exam and may recommend that you visit an ear, nose, and throat specialist for further evaluation and treatment.