Almost every article about pain types gives you a list. A list is not useful on its own. What is useful is knowing which category your pain falls into, because the category determines whether a treatment has any chance of working. An anti-inflammatory that resolves a sprained ankle in three days will do close to nothing for burning nerve pain in the feet. A nerve block that shuts down a facet joint completely will not quiet pain generated by the central nervous system itself.
This page covers how pain is actually classified in pain medicine — by mechanism, by duration, and by the tissue it comes from — and then the part most pages leave out: what each category changes about treatment.
Start with what pain is
The International Association for the Study of Pain revised its definition of pain in 2020 to “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.” Two things in that sentence do real work. Emotional is in the definition, not appended to it. And “or resembling that associated with” was added deliberately, so that pain occurring without demonstrable tissue damage is still pain, not a lesser category of complaint. That matters for the third mechanism below, which is the one most pain-type articles never mention.
The three pain mechanisms
Mechanism is the most clinically important axis, because it maps most directly onto treatment. There are three recognized mechanistic descriptors.
Nociceptive pain
Nociceptive pain arises from actual or threatened damage to non-nervous tissue — bone, muscle, ligament, tendon, joint capsule, skin. The nerves are working correctly; they are reporting a real problem in the tissue they monitor.
It usually behaves the way people expect pain to behave. It is proportional to the injury, it is worse with use and better with rest, it is often well localized, and it typically improves as the tissue heals. Descriptions run to aching, throbbing, sharp with movement, or a deep pressure.
Common examples: a fracture, osteoarthritis of the knee or hip, a rotator cuff tear, facet joint arthropathy, sacroiliac joint pain, post-surgical pain in the first days after an operation.
Neuropathic pain
Neuropathic pain is caused by a lesion or disease of the somatosensory nervous system itself. The problem is in the wiring, not in the tissue the wiring reports on. The nerve is generating a pain signal that does not correspond to tissue damage where the pain is felt.
It reads differently, and the difference is usually obvious once you know to listen for it. Patients describe burning, electric shocks, shooting, stabbing, pins and needles, crawling, or numbness that hurts. The pain follows a nerve territory rather than a joint or a muscle. Two findings are near-signatures: allodynia, where a normally painless stimulus — a bedsheet, a sock, a breeze — causes pain, and hyperalgesia, where a mildly painful stimulus causes far more pain than it should. Neuropathic pain also tends to be worse at night, which is one of the few clues that separates it from a mechanical problem in the same limb.
Common examples: diabetic peripheral neuropathy, postherpetic neuralgia after shingles, painful radiculopathy (which is what most people mean when they say sciatica), trigeminal neuralgia, pain after nerve injury during surgery, phantom limb pain, and central neuropathic pain after spinal cord injury or stroke.
Grading matters here. Rather than a yes-or-no label, neuropathic pain is graded as possible, probable, or definite, depending on whether the pain distribution is neuroanatomically plausible, whether examination confirms sensory signs in that territory, and whether a test confirms a lesion or disease of the somatosensory system. A useful caution from the group that wrote the grading system: even the “definite” level establishes that a lesion is present, not that it is necessarily the cause of the pain.
Nociplastic pain — the third category most pages miss
Nociplastic pain arises from altered nociception without clear evidence of tissue damage causing activation of peripheral nociceptors, and without evidence of disease or lesion of the somatosensory system causing the pain. Put plainly: the tissues look reasonable, the nerves test intact, and the pain is real and is being generated by changes in how the nervous system processes signals.
This is the newest of the three descriptors and the one that reorganizes how a large group of patients gets understood. Before it existed, these patients were sorted into whichever of the other two boxes fit worst, or told that nothing was found.
Published clinical criteria for chronic nociplastic pain affecting the musculoskeletal system require, among other things, that the pain be regional rather than discrete, present for at least three months, not entirely explained by nociceptive or neuropathic mechanisms, and accompanied by evidence of pain hypersensitivity in the painful region. Supporting features that raise confidence include hypersensitivity to sound, light or odor, sleep disturbance with non-restorative sleep, fatigue, and cognitive problems with attention or memory.
Common examples: fibromyalgia, many cases of persistent nonspecific low back pain, some temporomandibular disorders, irritable bowel syndrome, and interstitial cystitis or bladder pain syndrome.
Mixed pain — the ordinary case
Real patients are rarely one thing. A person with long-standing lumbar degeneration can have nociceptive facet pain, neuropathic radicular pain down one leg, and nociplastic amplification layered over both. The consensus recommendations for classifying low back pain by phenotype are explicit that the goal is identifying the dominant mechanism, not proving a single one — and that same consensus group notes the recommendations are an early step, not yet ready for routine clinical implementation without further evidence. That is an honest limit of the framework and worth knowing before anyone tells you a questionnaire has sorted you.
Acute pain and chronic pain
Duration is a second, separate axis. Any of the three mechanisms can be acute or chronic.
Acute pain is recent, has an identifiable cause in most cases, and resolves as the cause resolves. Biologically it is doing a job: it enforces rest and protects healing tissue.
Chronic pain is defined as pain that persists or recurs for more than three months. That three-month line is not arbitrary bureaucracy — it was adopted as the operational threshold in the ICD-11 classification of chronic pain.
The more consequential change in that classification is structural. Chronic pain is split into chronic primary pain, where the pain is a disease in its own right rather than a symptom of something else, and six categories of chronic secondary pain, where the pain follows from an identified underlying condition: cancer-related, neuropathic, visceral, post-traumatic and post-surgical, headache and orofacial, and musculoskeletal.
The reason to care as a patient: chronic primary pain is a positive diagnosis, not a diagnosis of exclusion. It does not mean nothing was found. It means the pain itself is the condition being treated.
Somatic and visceral pain
A third axis describes where nociceptive pain originates.
Somatic pain comes from the body wall and musculoskeletal structures. Superficial somatic pain — skin, mucosa — is sharp and precisely located. Deep somatic pain — muscle, bone, joint, fascia — is duller, aching, and harder to point at, but still reasonably localized.
Visceral pain comes from the internal organs, and it behaves unlike anything else. It is diffuse and poorly localized. It correlates loosely with the amount of organ damage. It is characteristically accompanied by autonomic responses — nausea, sweating, changes in heart rate and blood pressure — and by a strong negative emotional quality that patients often describe as sickening or frightening rather than simply painful. And it refers.
Referred pain, and why it fools people
Referred pain is felt somewhere other than where it is generated. The classic example is a heart attack felt in the left arm and jaw; gallbladder pain in the right shoulder blade; kidney pain in the groin.
The mechanism is convergence. Spinal visceral afferents project into the dorsal horn of the spinal cord onto viscerosomatic convergent neurons — cells that also receive input from the skin and deep somatic tissues of the corresponding segments. The brain receives a signal from a shared relay and attributes it to the body wall, which is where it has far more experience localizing sensation.
Referral is not limited to organs. Deep somatic structures refer too, in reproducible patterns: hip osteoarthritis into the knee, cervical facet joints into the head and shoulder, lumbar facet joints into the buttock and thigh. This is why the location a patient points to is a clue rather than an answer, and why a workup that only images the painful spot misses a substantial share of cases.
Why the category changes the treatment
This is the part that makes classification worth doing. The categories are not descriptive labels; they predict which interventions have a mechanism of action available to them.
Nociceptive pain
Responds to treatments that address the tissue and the nociceptive input: anti-inflammatory measures, load management and progressive loading, physical therapy, and image-guided interventional procedures aimed at the pain generator once it is identified — facet or medial branch procedures, sacroiliac joint procedures, epidural injections where an inflamed nerve root is the source, radiofrequency ablation of the nerves supplying a painful joint. Diagnostic blocks earn their place here because confirming the generator before treating it is what separates a targeted procedure from a guess.
Neuropathic pain
Responds poorly to standard anti-inflammatories, which is the single most common reason patients arrive convinced that nothing works. The medications with the strongest recommendation in the NeuPSIG systematic review and meta-analysis were tricyclic antidepressants, serotonin–noradrenaline reuptake inhibitors, pregabalin and gabapentin. It is worth stating what the numbers actually were, because the honest version is more useful than the confident one: combined numbers needed to treat for 50% pain relief were 6.4 for SNRIs, 7.7 for pregabalin, and 7.2 for gabapentin — meaning most patients in those trials did not reach 50% relief on a single drug. The authors concluded that inadequate response to drug treatment is a substantial unmet need. That is precisely the gap that interventional and neuromodulation approaches exist to address: nerve blocks, sympathetic blocks, and spinal cord or peripheral nerve stimulation.
Nociplastic pain
This is where treating the wrong category does active harm. Repeated procedures aimed at a structure that is not generating the pain produce repeated disappointment, and every negative result reinforces the belief that the pain is untreatable. Care here is built differently: graded activity and reconditioning, sleep restoration, treatment of the metabolic and inflammatory drivers where they are present, and psychological approaches with an evidence base in chronic pain, including Acceptance and Commitment Therapy, which the Padda Institute delivers in-house rather than referring out. Interventional procedures still have a role where a genuine nociceptive or neuropathic component is contributing — mixed presentations are the rule — but they are not the whole plan.
Visceral and referred pain
Requires finding the actual source. Where the source is identified and the pain persists despite treatment of the underlying condition, targeted sympathetic and plexus blocks are the interventional options — a celiac plexus block for upper abdominal visceral pain, for example.
What this framework cannot do
Two honest limitations, because a page that only sells the framework is not much better than a listicle.
The categories are descriptors, not diagnoses. Nociplastic pain in particular is defined partly by what it is not, which makes it dependent on how thoroughly the other two were ruled out. A hurried evaluation produces a nociplastic label the same way it produces a “nothing found” label.
The evidence base for mechanism-guided treatment is younger than the framework. The low back pain phenotyping consensus states directly that preliminary evidence suggests these phenotypes might respond differently to treatment, but that more research is needed before specific recommendations can be made. Anyone claiming that a classification questionnaire selects your treatment is ahead of the evidence.
There is a further problem that matters more for the patients this practice actually treats. Randomized trials of pain treatments routinely exclude people with significant metabolic dysfunction, obesity, diabetes, autoimmune and inflammatory disease, multiple comorbidities, polypharmacy, prior failed treatment, and long symptom duration. Those exclusions produce cleaner trials and a narrower answer. A modest result in a screened population does not establish that a treatment fails in the patients who were screened out, and it does not test what happens when treatments are combined or sequenced rather than given alone. Trials also tend to run short, which measures onset rather than durability. None of that is a reason to ignore the evidence; it is a reason to read it as a description of the population studied.
How the category actually gets determined
Not by a quiz. The working classification comes out of the history — what the pain feels like, where it goes, what provokes and relieves it, how it behaves at night — combined with a physical examination that looks specifically for sensory abnormality in a nerve territory and for hypersensitivity in the painful region. Where a neuropathic component is suspected, electrodiagnostic testing (EMG and nerve conduction studies) can confirm or exclude a lesion. Where a nociceptive generator is suspected, a diagnostic block confirms whether that structure is in fact producing the pain before anything is done to it.
Dr. Gurpreet Singh Padda, MD, MBA, MHP evaluates and treats all three mechanisms, including the mixed presentations that make up most of a pain practice. If your pain has been treated as one category and has not responded, the working hypothesis may be the thing that needs revisiting.
To be seen: call (314) 481-5000, text (314) 886-5902, or request an appointment. No referral is required, and you do not need to be an existing patient. Same-day appointments are available.
Frequently asked questions
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1. What are the main types of pain?
Pain is classified on three separate axes. By mechanism there are three types: nociceptive (from tissue damage), neuropathic (from a lesion or disease of the nervous system), and nociplastic (from altered pain processing without either of the first two fully explaining it). By duration, pain is acute or chronic, with three months as the dividing line. By source, nociceptive pain is somatic (body wall, muscles, joints) or visceral (internal organs). Most patients with long-standing pain have more than one mechanism running at once. Learn more: Why medications and surgery may not fix your pain.
2. What type of pain do I have?
The pattern usually points the way. Aching, throbbing pain that is worse with use and better with rest, and that you can localize, suggests nociceptive pain. Burning, shooting or electric pain that follows a nerve territory, is worse at night, or comes with numbness or hypersensitivity to light touch suggests neuropathic pain. Widespread pain lasting months with unrefreshing sleep, fatigue and sensitivity to sound or light suggests a nociplastic component. These overlap, so the working answer comes from a physical examination and, where indicated, nerve testing. Learn more: What EMG and nerve conduction studies measure.
3. What is nociplastic pain?
Nociplastic pain is pain arising from altered nociception without clear evidence of tissue damage activating peripheral pain receptors and without a demonstrable lesion of the somatosensory nervous system. It is a positive category, not a way of saying nothing was found. Fibromyalgia is the reference example. Published criteria require regional rather than discrete pain, present at least three months, with evidence of pain hypersensitivity in the affected region; supporting features include non-restorative sleep, fatigue, and sensitivity to sound, light or odor. Learn more: Fibromyalgia and how widespread pain is evaluated.
4. What is the difference between nociceptive and neuropathic pain?
Nociceptive pain comes from tissue — a joint, a muscle, a bone — with the nerves working correctly and reporting a real problem. Neuropathic pain comes from damage to the nerves themselves, so the signal no longer corresponds to tissue injury where the pain is felt. The practical consequence is large: nociceptive pain often responds to anti-inflammatory measures and to procedures targeting the tissue generator, while neuropathic pain frequently does not, and is approached with nerve-directed medications, nerve blocks and neuromodulation instead. Learn more: Why diabetic neuropathy burns worse at night.
5. When does acute pain become chronic pain?
The accepted threshold is three months of pain that persists or recurs, adopted in the ICD-11 classification of chronic pain. The classification also separates chronic primary pain, where the pain is the condition itself, from chronic secondary pain, where it follows an identified underlying disease. Passing the three-month mark does not mean the pain is permanent, but it does mean the evaluation should widen beyond the original injury. Learn more: What untreated chronic pain does to the brain.
6. What is referred pain?
Referred pain is felt in a location other than where it is produced. It happens because nerve fibers from internal organs and from deep somatic structures converge on the same spinal cord neurons that receive input from skin and muscle, and the brain attributes the signal to the body wall. Hip arthritis felt in the knee, gallbladder pain in the right shoulder blade, and cervical facet pain felt in the head are all referred pain. It is a common reason imaging the painful spot finds nothing. Learn more: Mid-back pain between the shoulder blades.
7. What is visceral pain and how is it different?
Visceral pain originates in the internal organs. It is diffuse and hard to localize, correlates poorly with how much organ damage is present, refers to other areas, and is characteristically accompanied by nausea, sweating and a strong sickening quality. Somatic pain from muscle, bone and joint is better localized and more proportional to the injury. When visceral pain persists despite treatment of the underlying condition, targeted plexus and sympathetic blocks are an option. Learn more: Celiac plexus block for upper abdominal pain.
8. Why does knowing my pain type matter?
Because it decides which treatments have a mechanism available to them. Anti-inflammatories work on inflamed tissue and do relatively little for damaged nerves. A block that quiets a facet joint will not help pain generated centrally. Procedures repeated against a structure that is not the generator produce repeated disappointment. Getting the category right is what turns a sequence of attempts into a plan. Learn more: Why pain injections stop working.
9. Can you have more than one type of pain at the same time?
Yes, and it is the usual situation in long-standing pain. Someone with lumbar degeneration can have nociceptive facet pain, neuropathic radicular pain in one leg, and nociplastic amplification over both. The consensus recommendations on classifying low back pain are explicit that the aim is identifying the dominant mechanism, not proving a single one. Treatment plans that address only one component in a mixed presentation tend to produce partial results. Learn more: Why leg pain persists after back surgery.
10. Which pain types respond to interventional procedures?
Nociceptive pain with an identifiable generator is where these procedures have the clearest mechanism available to them, which is why diagnostic blocks are used to confirm the source before a longer-acting procedure is done. Neuropathic pain has interventional options — nerve blocks, sympathetic blocks, spinal cord and peripheral nerve stimulation — that are frequently used precisely because medication response is often incomplete. Nociplastic pain is generally not fixed by a procedure alone, though a coexisting nociceptive or neuropathic component may still be worth treating. Learn more: How an epidural steroid injection works.
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Dr. Gurpreet Singh Padda, MD, MBA, MHP
