Tonsil aid tablets Sore throat is a inconvenience or suffering in the throat area which makes swallowing very difficult. It is because of the pharynx, (Pharyngitis, tonsillitis, and laryngitis). Most sore throats are caused by viral infections, such as a cold or flu, other reasons are toxins, irritants, trauma, or injury to the throat. A bacterial infection can also cause a sore throat. These types of infections include: strep throat, which is an inflammation of the throat caused by the Streptococcus pyogenes bacteria. Sore throat or throat pain can be contagious until they last (typically for a few days).