There are four vital signs doctors use to assess a patient’s wellbeing: body temperature, pulse rate, respiration rate, and blood pressure. These standard metrics of patient wellness are relatively objective; the numbers garnered from these assessments indicate how far from baseline health a patient is. Body temperature has been used as an indicator of patient wellness since at least 1851 in western medicine, and pulse rate has acted as a marker of wellbeing for thousands of years globally. Blood pressure was first evaluated in the early 1700s in Europe, and a century later became better understood and more standardized. Respiration rate (how many breaths a person takes per minute) can be traced back to, at the latest, 1892, when abnormally rapid breathing began to be diagnosed as tachypnea. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO), established in 1951, accepted these four vital signs as sufficient for over half a century. It wasn’t until 2001 that the JCAHO introduced patient pain as the fifth vital sign. Pain as the fifth vital sign didn’t quite fit with the others; while the other vital signs focused on standard quantitative metrics of wellness, pain was typically self-evaluated by patients, based on their own metrics. This new assessment shifted doctors’ goals when it comes to pain: try to decrease a number on a scale, rather than find underlying causes of patient pain.
This new vital sign is the only one that’s subjective. All other vital signs are derived from standardized medical technology that quantify how bodies function. Temperature, heart rate, respiration rate, and pulse can give us a standard idea of a patient’s wellness. But because we all experience pain differently, there’s no true standard for it; yet the pain scale is now customary across the nation. In the past twenty years, the pain scale has been used to determine if a patient’s complaint is urgent. But even this assessment of urgency is misguided. In the National Pain Report, columnist Liza Zoellick writes, “What if my ‘7’ sounds like I’m lying? What if they think I want more drugs? … When presented with this scale it feels like you are trying to fit my pain into your version of what you think it should be.” Doctors’ perceptions of patients will inevitably infiltrate how they understand someone’s assessment of pain.