Which type of pain is considered chronic?

Chronic pain is defined as pain that persists over a long period, typically longer than three months, and often continues beyond the expected period of healing after an injury. Pain from chronic conditions like arthritis falls under this category because it can be ongoing and associated with degenerative changes in the joints, leading to prolonged discomfort and functional impairment.

In contrast, post-operative pain is usually acute, as it tends to diminish as the surgical site heals. Acute inflammation is also a short-term response to injury or infection, typically resolving as the underlying issue is addressed. Retrospective pain after injury may refer to pain that occurs after an injury has healed, but it is not classified as chronic unless it persists for an extended period. Therefore, the option highlighting long-lasting pain from arthritis correctly identifies the nature of chronic pain.