Trigger points are hyperirritable spots in taut bands of skeletal muscle that cause local and referred pain. There is debate around whether trigger points are a peripheral or central nervous system phenomenon. The document discusses that referred pain from trigger points is a central phenomenon initiated by peripheral sensitization from the trigger point. Trigger points act as an ongoing source of nociception that can induce central sensitization. However, central sensitization may also promote trigger point activity. Proper treatment of trigger points can reduce central sensitization by decreasing nociceptive input.