Why rating your pain out of 10 is tricky

“It’s really sore,” my (Josh’s) five-year-old daughter said, cradling her broken arm in the emergency department.

“But on a scale of zero to ten, how do you rate your pain?” asked the nurse.

My daughter’s tear-streaked face creased with confusion.

“What does ten mean?”

“Ten is the worst pain you can imagine.” She looked even more puzzled.

As both a parent and a pain scientist, I witnessed firsthand how our seemingly simple, well-intentioned pain rating systems can fall flat.

What are pain scales for?

The most common scale has been around for 50 years. It asks people to rate their pain from zero (no pain) to ten (typically “the worst pain imaginable”).

This focuses on just one aspect of pain – its intensity – to try and rapidly understand the patient’s whole experience.

How much does it hurt? Is it getting worse? Is treatment making it better?

Rating scales can be useful for tracking pain intensity over time. If pain goes from eight to four, that probably means you’re feeling better – even if someone else’s four is different to yours.

Research suggests a two-point (or 30%) reduction in chronic pain severity usually reflects a change that makes a difference in day-to-day life.

But that common upper anchor in rating scales – “worst pain imaginable” – is a problem.

A narrow tool for a complex experience

Consider my daughter’s dilemma. How can anyone imagine the worst possible pain? Does everyone imagine the same thing? Research suggests they don’t. Even kids think very individually about that word “pain”.

People typically – and understandably – anchor their pain ratings to their own life experiences.

This creates dramatic variation. For example, a patient who has never had a serious injury may be more willing to give high ratings than one who has previously had severe burns.

“No pain” can also be problematic. A patient whose pain has receded but who remains uncomfortable may feel stuck: there’s no number on the zero-to-ten scale that can capture their physical experience.

Increasingly, pain scientists recognise a simple number cannot capture the complex, highly individual and multifaceted experience that is pain.

Who we are affects our pain

In reality, pain ratings are influenced by how much pain interferes with a person’s daily activities, how upsetting they find it, their mood, fatigue and how it compares to their usual pain.

Other factors also play a role, including a patient’s age, sex, cultural and language background, literacy and numeracy skills and neurodivergence.

For example, if a clinician and patient speak different languages, there may be extra challenges communicating about pain and care.

Some neurodivergent people may interpret language more literally or process sensory information differently to others. Interpreting what people communicate about pain requires a more individualised approach.

Impossible ratings

Still, we work with the tools available. There is evidence people do use the zero-to-ten pain scale to try and communicate much more than only pain’s “intensity”.

So when a patient says “it’s eleven out of ten”, this “impossible” rating is likely communicating more than severity.

They may be wondering, “Does she believe me? What number will get me help?” A lot of information is crammed into that single number. This patient is most likely saying, “This is serious – please help me.”

In everyday life, we use a range of other communication strategies. We might grimace, groan, move less or differently, use richly descriptive words or metaphors.

Collecting and evaluating this kind of complex and subjective information about pain may not always be feasible, as it is hard to standardise.

As a result, many pain scientists continue to rely heavily on rating scales because they are simple, efficient and have been shown to be reliable and valid in relatively controlled situations.

But clinicians can also use this other, more subjective information to build a fuller picture of the person’s pain.

How can we communicate better about pain?

There are strategies to address language or cultural differences in how people express pain.

Visual scales are one tool. For example, the “Faces Pain Scale-Revised” asks patients to choose a facial expression to communicate their pain. This can be particularly useful for children or people who aren’t comfortable with numeracy and literacy, either at all, or in the language used in the health-care setting.

A vertical “visual analogue scale” asks the person to mark their pain on a vertical line, a bit like imagining “filling up” with pain.

What can we do?

Health professionals

Take time to explain the pain scale consistently, remembering that the way you phrase the anchors matters.

Listen for the story behind the number, because the same number means different things to different people.

Use the rating as a launchpad for a more personalised conversation. Consider cultural and individual differences. Ask for descriptive words. Confirm your interpretation with the patient, to make sure you’re both on the same page.

Patients

To better describe pain, use the number scale, but add context.

Try describing the quality of your pain (burning? throbbing? stabbing?) and compare it to previous experiences.

Explain the impact the pain is having on you – both emotionally and how it affects your daily activities.

Parents

Ask the clinician to use a child-suitable pain scale. There are special tools developed for different ages such as the “Faces Pain Scale-Revised”.

Paediatric health professionals are trained to use age-appropriate vocabulary, because children develop their understanding of numbers and pain differently as they grow.

A starting point

In reality, scales will never be perfect measures of pain. Let’s see them as conversation starters to help people communicate about a deeply personal experience.

That’s what my daughter did — she found her own way to describe her pain: “It feels like when I fell off the monkey bars, but in my arm instead of my knee, and it doesn’t get better when I stay still.”

From there, we moved towards effective pain treatment. Sometimes words work better than numbers.