Inside the healthy tooth is the so-called tooth pulp, consisting of blood vessels and nerves. If the tooth is damaged by a deep caries or fracture, bacteria can enter the pulp. This leads to a sometimes painful inflammation, which irreversibly destroys the tissue of the pulp.
As the inflammation progresses, it spreads to the bone around the root tips. This can remain painless and unnoticed for a longer period of time, but can also change into an acute condition at any time.
In addition, the inflammation can trigger symptoms in widely branched parts of the body (so-called “chronic focus of inflammation”).