How do C fibres produce lingering and poorly localized pain?

C fibres produce lingering and poorly localized pain primarily due to their physiological structure. Unlike A delta fibres, which are larger and covered in a thin layer of myelin to conduct impulses rapidly, C fibres are smaller and unmyelinated.1

This lack of a myelin sheath results in slower conduction of electrical impulses from the tissues to the spinal cord. Consequently, while A delta fibres are responsible for the initial, sharp, and well-localized sensation of pain, the slower-conducting C fibres are associated with the dull, aching, and poorly localized sensation that follows. These fibres are activated by a variety of stimuli, including chemical, mechanical, and thermal sources.1