'Game-changer': New blood test can identify the colour of pain

It could soon be much harder to lie to a doctor about the level of pain you are experiencing.

That's because Australian scientists say they've discovered the "colour" of pain.

They've created a breakthrough blood test that identifies chronic pain based on the colour the cells create when examined with a special light imaging tool.

One in six New Zealanders lives with chronic pain. It's often misdiagnosed and misunderstood because it's so hard to accurately measure.

Australian neuroscientist Mark Hutchinson is leading a spot blood test that identifies chronic pain by colour "biomarkers" - quite literally quantifying the colour of pain.

"Being able to measure one of the most common reasons people go to the doctor - this is a game-changer," says Professor Hutchinson.

"We're able to use this multitude of colours to tell us whether the blood came from someone who had pain, or not."

It's revolutionary, especially for people who cannot describe their own pain - such as dementia patients and babies.

"These people cannot communicate the extent of pain or that they're in pain, so obviously knowing how much pain they're suffering will be an amazing thing to achieve just through a simple blood test."

While other blood tests have accurately diagnosed pain, it usually takes days. However this test gives instant results.

While it currently indicates only 'no pain' or 'chronic pain', it could eventually diagnose different levels of pain intensity.

"That is the next level of experiment we want to take this to," says Professor Hutchinson.