02
interoception
how you sense what is happening inside your own body
interoception meaning: the short answer
interoception is how your nervous system senses what is happening inside your body. a racing heart, a full bladder, hunger, a tight chest, a churning gut: each of those starts as a signal from inside, and interoception is the processing of those signals (Khalsa et al, 2018).
it is often called the sense of the body from the inside, alongside the senses that face outward, like sight and hearing. two things about it are less well known. most of it happens outside your awareness. and "being aware of your body" turns out to be several different abilities, which do not always agree with each other.
what interoception covers
the signals come from many of the systems that keep the body stable, including the heart and blood vessels, the lungs, the gut, the bladder and genitals, the immune system, the system that signals pain, and the systems that control body temperature and fluid balance (Khalsa et al, 2018).
the neuroscientist A. D. Craig grouped together feelings that seem unrelated at first: temperature, pain, itch, the burn in a working muscle, hunger and thirst. his argument was that they share one job. each reports on the physiological state of a part of the body, so the brain can keep it in balance (Craig, 2002).
how the signals reach the brain
there are two main routes in.
- through the spinal cord. small nerve fibres from the tissues report temperature, chemistry, strain and damage to the spinal cord, and a dedicated pathway carries that information up through the thalamus to the insula, a region folded deep inside the cortex (Craig, 2002).
- through the vagus nerve and other nerves from the organs, which carry signals from inside the body to the brainstem (Jänig, 2006).
Craig proposed that the back of the insula holds a basic map of the body's state, and that a region further forward, especially on the right side, re-represents that map in a way that becomes feeling. he described the system as a representation of "the material me", which might provide a foundation for feelings, emotion and self-awareness (Craig, 2002). much of the pathway was mapped in primates and humans. the claim that it is the basis of feeling and of the sense of self is a proposal, and still being tested.
the autonomic nervous system is continuously shaped by these incoming signals: they feed the circuits that send instructions back out to the organs (Jänig, 2006).
most interoception happens outside awareness
your brain is tracking your blood pressure all the time, through pressure sensors in the walls of the large arteries that report to the brainstem (Hall and Hall, 2026, ch 61). it is processing signals from the gut and other organs too, and you feel only some of it. most interoception runs outside conscious awareness. it is often, though not always, felt when something is out of balance (Khalsa et al, 2018).
that matters for anything you do with your body's signals. what you notice is a filtered part of what your nervous system is processing, not a full readout.
body awareness is three different things
if you ask someone how aware they are of their body, you might mean any of three things. a study of 80 people tested all three and found them distinct (Garfinkel et al, 2015).
- interoceptive accuracy: how well you do on a performance test, such as counting or detecting your own heartbeats without touching your pulse.
- interoceptive sensibility: how good you believe you are, measured by questionnaires and interviews.
- interoceptive awareness: how well your confidence tracks your actual accuracy. do you know when you are right? the multi-author review below calls this one insight.
accuracy was only partly predicted by the other two. the three lined up with each other only in the people who were most accurate (Garfinkel et al, 2015). put plainly: in this study, feeling in touch with your body and being accurate about it were not the same thing.
a later review by many researchers in the field goes further. the different ways of measuring interoception overlap only partly, probably reflect somewhat different processes in the brain, and the most common heartbeat tasks measure different aspects of it (Khalsa et al, 2018). when a study, a product or a post says it improves body awareness, it is worth asking which of these it means.
somatic awareness: what it can and cannot tell you
somatic awareness is a broader, less precisely defined term for noticing sensations in the body: tension, warmth, heaviness, restlessness. as this article uses it, it is closest to interoceptive sensibility, the self-reported kind.
it can tell you a lot about what you notice, and when. it cannot, on its own, tell you how accurate that noticing is, for the reasons above. a sensation you report is real as an experience. whether it matches what your heart, gut or muscles were actually doing is a separate question.
interoception and mental health
differences in interoception have been linked to anxiety, depression, eating disorders, addiction and disorders where physical symptoms dominate (Khalsa et al, 2018). this is one reason the field draws clinical interest.
the same review is careful about what this shows. there is limited evidence that interoceptive measures predict who has a disorder, how it will go, or how someone will respond to treatment. whether interoceptive differences cause problems or result from them is still an open question, particularly for problems that emerge as people develop, and the authors describe their own roadmap as a work in progress (Khalsa et al, 2018).
can you get better at it?
it is often said that interoceptive accuracy can be trained, like a muscle. the research cited here does not test that. the review describes treatments that work through interoception, such as interoceptive exposure, which it reports as effective in specific disorders, especially panic disorder, and notes that drug-assisted versions have few studies so far and have not reached clinical practice (Khalsa et al, 2018).
what can be said is narrower. a practice of noticing may change what you report about your body. whether it changes how accurate you are is a different claim, and this article does not make it.
where the evidence stops
- the pathways were mapped in primates and humans. Craig's account of how they become feeling and a sense of self is a proposal, not a settled finding.
- the three-part model of body awareness was tested in one study of 80 people (Garfinkel et al, 2015). a later multi-author review reports that the measures only partly overlap and that how best to measure them is not settled (Khalsa et al, 2018).
- links to mental health are associations. whether interoceptive differences cause problems or follow from them is not yet known, and there is limited evidence that the measures can predict who has a disorder, how it will go, or how someone will respond to treatment.
- symptoms and disorders are medical questions. this article does not cover them.
try this
pick one signal tonight, your heartbeat or your breath, and write one plain line about it: fast or slow, deep or shallow, easy to find or hard to find. then write how sure you are, from one to five. over a few days, the gap between how sure you are and how consistent your notes are tells you something about your own noticing. it does not measure accuracy, because nothing here checks your notes against your actual heart rate or breathing.
where the aware system fits
the aware system is a record of interoception at the level you can notice it: short entries for breath, body and mind, plus command (what you deliberately did) and regulate (what brought you back). it records what you noticed, not what your body measured, and it says so. read back over weeks, the record shows what you tend to notice, and when you tend to write "nothing". it is not a medical device, and there is no diagnosis. it opens on iOS and Android in february 2027.
read next
references
- Khalsa SS et al (2018). Interoception and mental health: a roadmap. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging 3(6):501-513. doi:10.1016/j.bpsc.2017.12.004
- Craig AD (2002). How do you feel? Interoception: the sense of the physiological condition of the body. Nature Reviews Neuroscience 3(8):655-666. doi:10.1038/nrn894
- Jänig W (2006). The Integrative Action of the Autonomic Nervous System: Neurobiology of Homeostasis. Cambridge University Press. doi:10.1017/CBO9780511541667
- Garfinkel SN, Seth AK, Barrett AB, Suzuki K, Critchley HD (2015). Knowing your own heart: distinguishing interoceptive accuracy from interoceptive awareness. Biological Psychology 104:65-74. doi:10.1016/j.biopsycho.2014.11.004
- Hall JE, Hall ME (2026). Guyton and Hall Textbook of Medical Physiology, 15th edition. Elsevier. chapter 61 (The Autonomic Nervous System and the Adrenal Medulla). ISBN 9780443111013