In 2001, the Joint Commission rolled out its Pain Management Standards, which helped grow the idea of pain as a "fifth vital sign." ... "Pain is a symptom, not a vital sign," the letter states, noting that vital signs such as blood pressure, heart rate, respiratory rate, and temperature can be measured objectively.

This is when it started. This set the pace for where we are today. When pain started being jumped on as the "5th" vital sign, that is what started sending people over the edge.