Short answer: Interoception is your sense of what is happening inside your body: hunger, thirst, tiredness, temperature, heartbeat, pain, and the need for the bathroom. Many autistic and ADHD adults notice these signals late, faintly, too strongly, or not at all, so they skip meals, forget water, and crash without warning. It can be supported with clock-based cues and regular body checks.
What is interoception?
Interoception is the sense that tells you about the inside of your body. It is how you know you are hungry, full, thirsty, too hot, about to need the toilet, or close to exhausted. It also carries the body side of emotions: the racing heart of fear, the tight stomach of dread, the heavy limbs of sadness.
Most of the time it runs in the background. A neurotypical person gets a gentle "you are hungry" around lunchtime, eats, and never thinks about it. For a lot of autistic and ADHD adults, that background process is quieter, louder, or patchier. The signal comes at 3pm as a shaky, furious crash. Or it comes as one vague "bad" feeling that could be hunger, anxiety, cold, or a full bladder, and you cannot tell which.
Researchers split interoception into a few parts. Accuracy is how well you detect a signal, often tested by asking people to count their heartbeats without touching their pulse. Sensibility is how good you believe you are at it. Awareness, or insight, is how well those two match (Klein et al., 2025). That last part turns out to matter: you can be confident you are fine while your body is running on empty.
Why is interoception called the eighth sense?
School teaches five senses: sight, hearing, smell, taste, and touch. Occupational therapists add two more that work inside the body: the vestibular sense, which handles balance and movement, and proprioception, which tells you where your limbs are. Interoception is often called the eighth sense because it completes that list. The first five face outward. The last three face inward.
The framing helps because it puts interoception next to sensory differences many autistic people already know. If sounds and lights can be too loud or too quiet, signals from inside the body can be too.
What are the signs of interoception differences?
These are common patterns, not rules, and you might recognize some and not others.
1. You forget to eat, then crash
No hunger signal all morning, then sudden shakiness, irritability, or a headache in the afternoon. People often describe going from "fine" to "starving and furious" with nothing in between.
2. You do not notice thirst
The first sign of dehydration is a headache, fatigue, or a foggy brain, not a dry mouth. Water bottles get filled and left full.
3. Tiredness arrives as a collapse
You feel fine, and then you are done. This is common after a long focus session or a social event.
4. Bathroom signals come late and urgent
The signal shows up only when it is already pressing, which makes long meetings, car trips, and deep focus harder to manage.
5. Temperature is confusing
You realize you are cold only when you are shivering, or you wear a coat in summer because the body never sent the update.
6. Pain and illness are hard to read
Some autistic and ADHD adults barely notice injuries or illness until they are serious. Others feel ordinary sensations, like a heartbeat or a full stomach, as loud and alarming. Both are interoception differences.
7. Emotions and body states blur together
Anxious or hungry? Angry or overheated? If you often cannot tell, you are describing the overlap between interoception and emotional awareness, which is where alexithymia, the trouble naming your own feelings, comes in.
Is interoception different in autistic adults?
For many autistic adults, yes, but the research is more mixed than social media suggests. A 2023 meta-analysis of 15 studies found autistic participants were less accurate at counting their own heartbeats than neurotypical participants, and more confident in their answers. On other measures, the groups were similar (Williams et al., 2023). A 2025 review of 31 studies found no consistent difference in heartbeat accuracy among autistic adults, and inconsistent results for other parts of interoception, partly because studies measure it in very different ways (Klein et al., 2025).
One explanation for the mixed picture is alexithymia. When researchers measured autism and alexithymia separately, it was alexithymia, not autism, that predicted weaker interoceptive accuracy (Shah et al., 2016). Since about half of autistic adults score high on alexithymia, interoception differences are common in autism without being universal.
The confidence finding is worth sitting with. If you feel sure you are not hungry and not tired, and your body disagrees, you will keep skipping meals in good faith. That is not carelessness. It is a mismatch between signal and certainty, and it is why external cues help so much.
Does ADHD affect interoception?
The ADHD research is newer and smaller, but it points the same way. A 2025 study comparing 30 ADHD adults with 57 adults without ADHD found the ADHD group was less accurate at detecting heartbeats, less confident, and rated their own body awareness lower, even after accounting for autistic traits, alexithymia, and depression (Goz Tebrizcik et al., 2025). The authors call for caution because the sample was small.
Eating is where it shows most. In a six-month study of 345 adults, weaker reliance on hunger and fullness cues helped explain the link between inattentive ADHD symptoms and both restrictive and binge-type eating (Martin et al., 2023). In plain terms: if you do not feel hunger until it is extreme, you tend to skip meals and then overeat, and that pattern is more about missed signals than willpower.
ADHD adds a second layer. Even when a signal does arrive, hyperfocus can override it. Six hours into a project, the body has been asking for food and water for a while, and attention simply did not let the message through. If you are AuDHD, you may get both: a quiet autistic signal and an ADHD attention system that walks past it.
How is interoception linked to sensory overload and autistic burnout?
Interoception is a sensory channel, so it shares a budget with the others. Hunger, thirst, a full bladder, and being too warm are all incoming signals, even when you cannot name them. Add a loud room and bright lights, and the total load can tip into sensory overload faster than you expect. Often the quickest way to lower overload is to fix the body inputs you were not noticing: eat, drink, cool down, use the bathroom.
The link with burnout is slower. Autistic burnout has been defined as chronic exhaustion, loss of skills, and reduced tolerance to stimulus, built up over time (Raymaker et al., 2020). If your body's "slow down" and "eat something" messages do not reach you, you can run past your limits for weeks without the usual warnings. Many autistic adults describe recognizing burnout only once it has fully arrived. Our page on autistic burnout covers the early signs to watch for, and many of them are body signs.
The same pattern shows up in shorter form with meltdowns: a day of missed meals and unnoticed stress makes a small trigger feel enormous.
What missed body signals look like, and what to try
| Signal | How it often shows up when missed | A cue that does not rely on the signal |
|---|---|---|
| Hunger | Shaky, irritable, headache, sudden crash | Meals at set clock times |
| Thirst | Headache, fatigue, brain fog | Same bottle always in reach, two-hour alarm |
| Tiredness | Fine, then done, or wired late at night | Bedtime alarm 30 minutes before bed |
| Bathroom | Late, urgent signal | Go at every transition: before leaving, before meetings |
| Temperature | Irritable, restless, cannot focus | Check the weather and dress in layers |
| Stress building | Meltdown or shutdown "out of nowhere" | A 1 to 10 check three times a day |
| Pain or illness | Noticed late, or felt as general "bad" | Ask: when did I last eat, drink, sleep, move? |
How do you support interoception day to day?
The core idea is simple: if the inside signal is unreliable, put the signal outside. Clocks, alarms, objects, and routines do the noticing for you. Start with one or two of these.
1. Eat to the clock, not to hunger
Pick fixed times, such as 8am, 12:30pm, and 6:30pm, and eat at those times whether or not you feel hungry. Many autistic adults have no hunger signal in the morning; eat something small anyway. The signal often turns up later, and by then you have already refueled.
2. Make water automatic
Use the same bottle every day and keep it within arm's reach. Add an alarm every two hours. If the taste of tap water bothers you, find water that tastes neutral to you, because most people drink more once the water tastes right.
3. Do a body check three times a day
Morning, midday, evening. Ask five questions in order: Am I hungry? Thirsty? Tense? Cold or hot? Do I need the bathroom? Many people find the answer is yes to more than one. Doing this at the same times each day is how the inside signals start to get clearer.
4. Build a post-focus protocol
When you come out of a long hyperfocus block, assume your body is in deficit. Water, something with protein, a few minutes of stretching. Write the protocol down, because you will not think of it in the moment. For long sessions, set a 90-minute timer for a water and snack break.
5. Keep one no-prep food in reach
A jar of nuts on the counter, crackers in your bag, a snack in the car. When the hunger signal arrives late and loud, you need fuel in minutes, not a meal that takes half an hour to make.
6. Use describing words for body states
When something feels "bad," try describing it instead of judging it: tight, hot, heavy, buzzy, hollow, shaky. A description is easier to act on. "Hollow and shaky" points to food. "Hot and tight" points to cooling down or leaving the room.
7. Track patterns for two weeks
Note when crashes, headaches, and meltdowns happen, and what you had eaten, drunk, and slept beforehand. Patterns that are invisible day to day often jump out over two weeks, and they tell you where to put your alarms.
8. Ask about structured interoception training
Interoception can be trained. In a randomized trial with 121 autistic adults, six sessions of heartbeat detection practice with feedback reduced anxiety three months later, and 31 percent of that group met the trial's recovery criteria, compared with 16 percent of the control group (Quadt et al., 2021). This was a clinical program run by researchers, not a home exercise, but it is worth asking a therapist or occupational therapist about body-awareness work.
Several of these routines come straight from 365 Tips for Autistic Adults, which has a full thread of interoception tips alongside sensory, routines, burnout, and work. It is one short tip a day, written from a decade of autistic-led community experience, and you can open it anywhere.
365 Tips for Autistic Adults (ours)
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Can interoception affect sleep?
Yes. Tiredness is an interoceptive signal, and when it is quiet, bedtime drifts. You may feel wide awake at midnight and pay for it the next day. Clock-based cues help here too: a gentle "go to bed now" alarm 30 minutes before bed starts the wind-down before the body would have asked. Our page on ADHD and sleep covers the rest of the picture.
When should you talk to a doctor?
Interoception differences are not an illness, but they can hide one. Talk to a doctor if you often notice illness or injury late, if you have frequent headaches, stomach problems, or dizziness without a clear cause, or if eating has become very irregular, very restricted, or out of control. Tell them you may not feel body signals the usual way, and talk to a doctor before big changes to how you eat, like fasting.
We run AuDHD Feed (@audhd_feed), ADHD Today (@adhd_today) and Autism Feed (@autism_feed), part of a family of neurodivergent pages reaching more than two million followers, and "I forgot to eat again" is one of the most common things people tell us. It is not a discipline problem. It is a sense that works differently, and it responds well to structure.
If the tired signal is the one you miss most, The AuDHD Sleep Workbook has a section on the missing tired signal, a sensory sleep profile, and a 14-night tracker. For everyday cues across food, water, sensory load, and routines, 365 Tips for Autistic Adults is the place to start.
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This page is information, not medical advice.
Frequently asked questions
What is interoception in simple terms?
Interoception is your sense of what is happening inside your body. It tells you when you are hungry, full, thirsty, tired, too hot or cold, in pain, or need the bathroom. It also carries the physical side of emotions, like a racing heart or a tight stomach. Most people never think about it until it works differently for them.
What is the eighth sense?
The eighth sense is a common name for interoception. Alongside the five outward senses (sight, hearing, smell, taste, touch), occupational therapists count two more inside the body: the vestibular sense for balance and proprioception for body position. Interoception, the sense of internal states like hunger and heartbeat, makes eight.
Do autistic people have poor interoception?
Many do, but not all. A meta-analysis found autistic participants were less accurate at sensing their heartbeat and more confident than they should be, while other measures were similar. Research suggests alexithymia, which affects about half of autistic adults, explains much of the difference. Some autistic people also feel internal signals too strongly rather than too weakly.
Is interoception a problem in ADHD?
Early research says it can be. A 2025 study found ADHD adults were less accurate at detecting heartbeats and rated their own body awareness lower than other adults. Missed hunger and fullness cues also help explain why inattentive ADHD symptoms are linked to irregular eating. Hyperfocus adds to it by blocking signals that do arrive.
Why do I forget to eat?
If you are autistic or ADHD, a common reason is that the hunger signal arrives late, faintly, or gets blocked by hyperfocus. You feel fine until you suddenly feel shaky and irritable. Eating at fixed clock times, keeping a no-prep snack in reach, and setting a timer during long focus sessions replace the missing signal with an outside one.
How can I improve my interoception?
Do short body checks at the same times each day, asking whether you are hungry, thirsty, tense, cold, or need the bathroom. Describe sensations in plain words like tight, heavy, or hollow. Track crashes and headaches for two weeks to spot patterns. Structured interoception training with a therapist has also reduced anxiety in autistic adults in a clinical trial.
Is interoception the same as alexithymia?
No, but they overlap. Interoception is sensing body signals of every kind, such as hunger, heartbeat, and temperature. Alexithymia is difficulty identifying and describing emotions. Because emotions are partly body states, people with high alexithymia often have weaker interoception too, and research suggests alexithymia explains many interoception differences seen in autism.
Can poor interoception cause meltdowns?
It can make them more likely. Missed hunger, thirst, tiredness, and building stress all add to your load without you noticing, so a small trigger can tip you over. Many autistic adults find meltdowns drop when they eat, drink, and rest on a schedule, and when they check in with their body a few times a day.
Sources
Williams ZJ, Suzman E, Bordman SL, et al. Characterizing interoceptive differences in autism: a systematic review and meta-analysis of case-control studies. Journal of Autism and Developmental Disorders, 2023. https://doi.org/10.1007/s10803-022-05656-2
Klein M, Witthoft M, Jungmann SM. Interoception in individuals with autism spectrum disorder: a systematic literature review and meta-analysis. Frontiers in Psychiatry, 2025. https://doi.org/10.3389/fpsyt.2025.1573263
Shah P, Hall R, Catmur C, Bird G. Alexithymia, not autism, is associated with impaired interoception. Cortex, 2016. https://doi.org/10.1016/j.cortex.2016.03.021
Goz Tebrizcik B, Georgescu AL, Pick S, Dommett EJ. Interoceptive abilities in adults with attention deficit hyperactivity disorder. Biological Psychology, 2025. https://doi.org/10.1016/j.biopsycho.2025.109161
Martin E, Dourish CT, Higgs S. Interoceptive accuracy mediates the longitudinal relationship between ADHD inattentive symptoms and disordered eating in a community sample. Physiology and Behavior, 2023. https://doi.org/10.1016/j.physbeh.2023.114220
Raymaker DM, Teo AR, Steckler NA, et al. Defining autistic burnout. Autism in Adulthood, 2020. https://doi.org/10.1089/aut.2019.0079
Quadt L, Garfinkel SN, Mulcahy JS, et al. Interoceptive training to target anxiety in autistic adults (ADIE): a single-center, superiority randomized controlled trial. EClinicalMedicine, 2021. https://doi.org/10.1016/j.eclinm.2021.101042