In stochastic processes, chaos theory and time series analysis, detrended fluctuation analysis (DFA) is a method for determining the statistical self-affinity of a signal.
Sore throats caused by tonsillitis or streptococcus may trigger a canker sore even after the initial throat condition has subsided. Also known as an aphthous ulcer, canker sores are painful and unsightly, but they are not contagious.
Multiple factors may cause canker sores, including injury to the mouth, acidic or spicy foods, vitamin deficiencies, hormones, stress, or autoimmune disorders. Canker sores are not the same thing as fever blisters (cold sores). Most canker sores require no treatment and heal on their own.