This is due to its aetiology; inflammatory exudate can be quickly removed, e.g. through a large carious cavity or previous trauma that caused painless pulp exposure. The build-up of pressure in a confined pulp space initiates pain reflexes. When this pressure is relieved, pain subsides.

As the names imply, these diseases are largely characterised by their symptoms: pain duration and location, and exacerbating and relieving factors. Inputs include clinical tests (cold ethyl chloride, EPT, hot-gutta percha,