Nociplastic pain, the third kind of pain.

What does nociplastic pain mean?

In their 2021 review in The Lancet, Mary-Ann Fitzcharles, Daniel Clauw and colleagues described nociplastic pain as a third category that is mechanistically distinct from the other two. Its mechanisms are not fully understood, but augmented pain and sensory processing in the central nervous system, along with altered pain modulation, are thought to play the leading roles.

People with nociplastic pain often report pain in several body regions, pain that is more intense than any visible tissue problem would explain, and other symptoms that seem to come from the central nervous system: fatigue, poor sleep, memory difficulties and mood changes. Nociplastic pain can occur on its own, as in fibromyalgia or tension-type headache, or mixed with nociceptive or neuropathic pain, as often happens in chronic low back pain.

The practical point the authors emphasized is the one that changes treatment. Nociplastic pain tends to respond less well to treatments aimed at the periphery, such as anti-inflammatory drugs, opioids, surgery or injections.

How do clinicians recognize nociplastic pain?

Naming a category is only useful if clinicians can identify it. In 2021, Eva Kosek and colleagues proposed clinical criteria and a grading system for chronic nociplastic pain affecting the musculoskeletal system (Kosek et al., 2021). The criteria weigh the duration and distribution of pain, the absence of a sufficient nociceptive or neuropathic explanation, signs of pain hypersensitivity, and associated symptoms such as sleep problems, fatigue and cognitive complaints.

In 2024, an international consensus group published recommendations specifically for classifying low back pain as nociceptive, neuropathic, nociplastic or mixed (Nijs et al., 2024). This kind of phenotyping is meant to match people with treatments that fit their dominant mechanism, rather than treating every back as if it had the same problem.

Is nociplastic pain the same as central sensitization?

The terms travel together, but they are not the same thing. Central sensitization describes a state in which neurons in the spinal cord and brain become more responsive, so that ordinary input is amplified. Reviews have linked these states to neuroinflammation (Ji et al., 2018) and to changes in brain function and structure, immune processing and peripheral factors (Kaplan et al., 2024). People with nociplastic pain are often diffusely tender and can be more sensitive than others to non-painful stimuli such as light, odors and noise.

It is worth being careful here. Central sensitization is a neurophysiological concept, much of it studied in animals, and it is hard to measure directly in people. A 2024 critical review asked whether chronic pain is in fact caused by central sensitization and urged caution about treating the two terms as interchangeable (Velasco et al., 2024). Even the researchers who championed the nociplastic concept have written about where it needs to go next (Kosek et al., 2024).

Why does the nociplastic label change treatment?

If pain is being driven largely by changes in how the nervous system processes signals, it makes sense to choose treatments that target the nervous system and the person's relationship with their pain rather than the tissues. The approaches with the best support include:

• Pain neuroscience education, which helps people understand why their pain persists and reduces threat. Reviews in people with signs of central sensitization have examined this directly (Lepri et al., 2023). See does it work?
• Graded movement and exercise, which help the nervous system relearn that activity is safe.
• Psychological approaches such as pain reprocessing therapy, cognitive behavioral therapy and acceptance-based therapies, which address fear, attention and beliefs.
• Attention to sleep, stress and mood, all of which influence pain processing.

Recognizing nociplastic features can also help clinicians and patients avoid an endless search for a structural cause, or repeated procedures that are unlikely to help. Our guide to chronic pain treatment lays out the options and the evidence behind each.

Does nociplastic mean the pain is not real?

No. Telling someone their pain is central or nociplastic can be heard as "it's not real" or "it's in your head", and that is never the message. Nociplastic pain is real pain produced by a real nervous system. A useful framing for patients is that the alarm system has become more sensitive, and that sensitivity can often be turned down with the right combination of understanding, movement and support.

The concept is still being refined, and its relationship to central sensitization is debated. But it has already changed how clinicians think about treatment, steering care toward approaches that work with the nervous system rather than chasing causes that scans cannot find. Karuna's program is designed for exactly this kind of pain; see how it works.