Which type of pain is classified as resulting from tissue injury?

Nociceptive pain is classified as pain that arises from tissue injury. This type of pain occurs when nociceptors, which are sensory receptors responsible for detecting harmful stimuli, are activated due to tissue damage. Nociceptive pain can be further divided into two categories: somatic pain, which originates from peripheral tissues such as skin, muscles, and bones, and visceral pain, which comes from internal organs. This distinction highlights nociceptive pain as the body's natural response to injury, serving a protective function by signaling that something is wrong.

In contrast, neuropathic pain arises from damage or dysfunction in the nervous system itself, making it a different classification altogether. Chronic pain is defined more by its duration and persistence rather than by its source, while functional pain refers to pain without a clear physical cause, often linked to abnormalities in the nervous system's processing of pain. Thus, nociceptive pain specifically relates to the direct consequence of tissue injury.