What is the difference between acute and chronic pain?

Acute pain is pain as a result of tissue damage from trauma, surgery, inflammation and is an appropriate response to injury.  It is also described as "nociceptive" pain, and should resolve once the tissue damage has healed, typically within 3 months of surgery.

A description of the physiology and management of nociceptive pain can be found here: Physiology and management of nociceptive pain.

Pain that continues for longer than 3 months after surgery, providing ongoing inflammatory processes such as infection have been excluded, is termed chronic post-surgical pain.

Chronic pain is pain that has persisted for more than 3 months with no evidence of ongoing tissue damage.  It represents a dysfunctional pain system and is divided into "neuropathic" and "nociplastic" pain.  A description of the physiology and management of neuropathic and nociplastic pain can be found here:  Physiology and management of neuropathic pain

However, some patients may experience acute neuropathic pain after damage to nerves during trauma or surgery.