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.
Several conditions can cause a sore throat. Sore throats may be caused by a viral illness, such as: 1  The common cold, the most common type of viral infection. 2  Infection of the voice box (laryngitis  ). Mononucleosis (mono, the kissing disease), a viral infection that tends to cause a persistent sore throat.