By Naomi Elste: Complete Post through this link…

The science of pain is complex and its assessment subjective, leading to bias and health inequality. Now, researchers are searching for a reliable, objective measure of pain.

ow much does it hurt? You might think it’s one of the simplest questions in health and medicine. But in fact, it can be a remarkably difficult question to answer objectively.

Consider a doctor who has two patients who are grimacing and using similar words to describe their pain. Can the doctor be sure they are experiencing similar levels of pain? What if one habitually underestimates their suffering? What if one has been in pain for a long time and grown used to it? And what if the doctor has certain prejudices that mean they are more likely to believe one patient than the other?

Pain is a difficult beast to grapple with, hard to measure and therefore to treat. Pain can be an important distress signal and failing to investigate it could mean a missed opportunity to save a life – or it may be something much more minor. 

For such a universal experience, pain remains much of a mystery – especially the task of determining how much pain someone is in. “We understand it so poorly,” says Emma Pierson, a computer scientist at Stanford University researching pain. “In particular, the fact that human doctors are frequently left flummoxed by why a patient is in pain suggests that our current medical understanding of pain is quite bad.”

The gold standard for pain analysis currently relies on patients self-reporting how they feel, relying, in different places, on either a numerical scale (0 as no pain, 10 as worst pain), or a system of smiley faces.

(T)here is the problem about whether the patient’s rating is believed. One study found a widespread notion that people tend to exaggerate the level of pain they are in, despite little evidence to suggest such exaggeration is common.