Sleepiness vs. Fatigue: Rethinking Insomnia Through Interoceptive Awareness

This article offers a mindfulness-based lens for helping clients rebuild interoceptive awareness of sleep cues, interrupt hyperarousal, and restore trust in their body’s natural capacity for sleep.

Insomnia is rarely just a problem of sleep. It is often a cycle of effort and arousal: going to bed early, lying still, watching the clock, trying harder—while the body remains alert. Paradoxically, the more effort applied, the less sleep seems to come.

“Insomnia isn’t a failure of sleep—it’s what happens when the focus shifts from allowing sleep to happen to trying to make sleep happen,” says Jason Ong, PhD, clinical psychologist and board-certified behavioral sleep medicine specialist.

A clinically useful distinction sits at the heart of this shift: the difference between sleepiness and fatigue. Although many people use these terms interchangeably, from a sleep medicine perspective, they reflect different states. When this distinction is blurred, bedtime decisions are guided by exhaustion rather than biological readiness—quietly sustaining the cycle of insomnia.

Mindfulness-based approaches to insomnia help reorient attention away from controlling sleep and toward sensing the body’s internal cues. By rebuilding interoceptive awareness, clients can begin to make bedtime decisions that align with their biology rather than forcing the body to do something before it is ready —reducing struggle and restoring trust in sleep as a natural process.

This article draws from Jason Ong’s teachings in Mindfulness-Based Therapy for Insomnia and the upcoming workshop Managing Insomnia with Mindfulness-Based Inquiry and Practices for Racing Thoughts. It offers a practical lens on how sleepiness and fatigue differ, how insomnia is maintained when cues are misread, and how clinicians can support a shift from striving to allowing

Contents:

1. Sleepiness Is a Biological Drive; Fatigue Is a State of Depletion
2. Guiding Bedtime Decisions by Internal Cues Rather Than the Clock
3. Why Mindfulness-Based Therapy for Insomnia Isn’t About “Meditating People to Sleep”
4. Building Interoceptive Awareness: Learning the Body’s Language of Sleep
5. Learn More: Managing Insomnia with Mindfulness-Based Inquiry and Practices for Racing Thoughts

Sleepiness Is a Biological Drive; Fatigue Is a State of Depletion

In sleep medicine, sleepiness refers to the propensity to fall asleep when given the opportunity. When sleepiness is present and conditions are supportive, sleep tends to occur quickly and with relative ease. It is regulated by homeostatic sleep drive and circadian rhythm and serves as the body’s internal signal that sleep is ready to happen.

Fatigue, by contrast, is a broader state of depletion. It may include low energy, mental fog, or lethargy and can arise from many sources, including stress, illness, emotional strain, or prolonged cognitive effort. Importantly, fatigue is not a direct signal from the sleep system. A person can feel profoundly fatigued but unable to fall asleep.

This distinction matters clinically because fatigue does not reliably lead to sleep. Clients may feel utterly depleted, go to bed early, and then lie awake for hours—confused and frustrated that sleep does not come despite how “tired” they feel.

When clients enter bed without sufficient sleep drive, the bed can become a place of monitoring and arousal rather than a place where sleep naturally unfolds. Jason Ong describes this state as “tired but wired”: the body feels depleted, but the sympathetic nervous system remains activated. Over time, repeated nights of wakefulness in bed strengthen the association between the bed and alertness, quietly maintaining insomnia.

Guiding Bedtime Decisions by Internal Cues Rather Than the Clock

Many people with insomnia make bedtime decisions based on external cues: the clock, next-day demands, or beliefs about how much sleep they should get. Structured approaches such as Cognitive Behavioral Therapy for Insomnia (CBT-I) are well supported by research and effective for many people, but they are not helpful or tolerable for everyone—particularly those who become more aroused when trying to follow sleep “rules.” For these individuals, following rules can increase pressure and performance anxiety around sleep.

Mindfulness-based approaches emphasize a different orientation. Instead of asking, “What time is it?” clients are invited to ask, “What is my body signaling right now?” This shift moves bedtime decisions away from effort and obligation and back toward biological readiness.

Why Mindfulness-Based Therapy for Insomnia Isn’t About “Meditating People to Sleep”

A common misconception is that mindfulness practices are tools for inducing sleep. In Mindfulness-Based Therapy for Insomnia (MBTI), this framing is intentionally avoided. Mindfulness is not used to make sleep happen; it is used to change the client’s relationship to wakefulness, effort, and internal cues.

Practices such as body scans or the “trainspotting” meditation function as forms of interoceptive training. They help clients notice sensations, thoughts, and arousal states without immediately reacting or trying to fix them. This shift targets what Ong describes as metacognitive arousal—the layer of striving, monitoring, and attachment that amplifies hyperarousal and maintains insomnia.

Sometimes clients fall asleep during mindfulness practices, which may indicate that sleepiness was present but previously unrecognized. At other times, especially early in treatment, mindfulness increases awareness of restlessness rather than resolving it. Both outcomes are clinically useful, as they provide a closer connection to what the body is signaling rather than something to manage or correct.

The key stance is curiosity rather than control. Mindfulness offers a platform for informed action, not a technique for achieving a particular outcome. By reducing struggle and restoring trust in bodily signals, sleep is allowed to emerge on its own terms.

Building Interoceptive Awareness: Learning the Body’s Language of Sleep

A core skill in mindfulness-based work with insomnia is helping clients develop interoceptive awareness—the capacity to notice and interpret internal bodily signals. Rather than explaining the difference between sleepiness and fatigue conceptually, this work invites clients to feel the distinction directly, in real time.

When sleepiness is present, clients often notice sensations such as heaviness around the eyes, head nodding, slowing of thoughts, or difficulty staying alert. There may be a natural pull toward sleep, as if the body is gently drawing itself in that direction.

Fatigue, by contrast, is typically experienced as depletion without sleep readiness. Clients may notice low energy, mental fog, heaviness, or restlessness alongside thoughts like, “I’m exhausted, but my mind won’t shut off,” or “I want to lie down, but I’m not sleepy.” These signals often point toward a need for care, restoration, or reduced stimulation rather than bed.

Clinicians can support clients in building interceptive awareness of body cues to discern between these states through simple, sensation-based inquiry that slows the process and brings attention out of the head and into the body. Helpful prompts include:

• What sensations are most noticeable in your body right now?
• What do you notice around the eyes, head, or face?
• Is there a sense of heaviness or drifting, or more restlessness and alertness?
• Do you feel a pull toward sleep, or more of a desire to rest or stop?
• If you were to lie down now, does your body feel ready to fall asleep—or more likely to stay awake?

Over time, clients learn to pause, read these cues, and respond accordingly. When sleepiness is present, going to bed supports the natural unfolding of sleep. When fatigue is present without sleepiness, choosing low-stimulation, nurturing activities outside of bed can reduce struggle and preserve the bed–sleep association.

The reframe is simple but clinically powerful: fatigue calls for care; sleepiness calls for bed.

Learn More: Easing the Cycle of Distress in Serious Illness: Three Mindfulness Approaches for Clinical Therapeutic Work

Interested in learning more? You can deepen your understanding of these mindful, compassionate ways of working with distress in our workshop: Managing Insomnia with Mindfulness-Based Inquiry and Practices for Racing Thoughts with Dr. Jason Ong.

Through this experiential, practice-based resource, you’ll explore how insomnia is maintained by cycles of effort, hyperarousal, and misinterpreted sleep cues—and how mindfulness can help interrupt that cycle. You’ll be guided through the train-spotting meditation for working skillfully with racing thoughts, along with inquiry practices that build interoceptive awareness of sleepiness versus fatigue. The workshop includes high-definition video lessons with professional transcripts, and practical guidance for integrating these tools into clinical work in clear, flexible, and evidence-informed ways.

Feel free to share this post with friends, family, or colleagues. Thanks for your ongoing interest and support!

Dr. Jason Ong is a licensed clinical psychologist and a Diplomate in Behavioral Sleep Medicine. He is currently the Director of Behavioral Sleep Medicine and Clinical Science at Nox Health where he is responsible for overseeing behavioral aspects of a telehealth sleep program and directing the clinical science team. Prior to joining Nox, Dr. Ong was an Associate Professor of Neurology at Northwestern University, where he was Director of the Behavioral Sleep Medicine Program and maintained an NIH-funded program of research that specialized in developing and testing mindfulness-based approaches for sleep disorders and authored the book  Mindfulness-Based Therapy for Insomnia. His leadership in academia combined with his industry experience in health tech provides a unique perspective and a leading voice on the intersection of sleep science, behavioral medicine, and digital health.

Sarah Kraftchuk, MSc, RP (qualifying), is Head of Learning at the Mindful Institute. She is a licensed clinician, certified mindfulness facilitator, art therapist, and children’s book author. 

Michael Apollo, MHSc, RP, is a licensed clinician, mindfulness educator, and Founder of the Mindful Institute. With over 15 years of experience, he specializes in practical, evidence-based mindfulness training for helping professionals. Formerly Director of Mindfulness Programs at the University of Toronto, Michael has collaborated with organizations like the World Health Organization, the UK NHS, and the Canadian Parliament to support mental well-being and resilience in diverse settings.

References:

Ong, J. C., Ulmer, C. S., & Manber, R. (2012). Improving sleep with mindfulness and acceptance: A metacognitive model of insomnia. Behaviour Research and Therapy, 50(11), 651–660. https://doi.org/10.1016/j.brat.2012.08.001

Ong JC, Manber R, Segal Z, Xia Y, Shapiro S, Wyatt JK. A randomized controlled trial of mindfulness meditation for chronic insomnia. Sleep. 2014 Sep 1;37(9):1553-63. doi: 10.5665/sleep.4010. PMID: 25142566; PMCID: PMC4153063.

Ong, J. C. (2017). Mindfulness-based therapy for insomnia. American Psychological Association. 

Perini et al. (2021); Perini, F. Wong, K.F., Lin, J., Hassirim, Z., Ong, J.K., Lo, J., Ong, J.C., Doshi, K., & Lim, J. (2023). Mindfulness-based therapy for insomnia for older adults with sleep difficulties: a randomized clinical trial. Psychological Medicine, 53(3), 1038-1048.

Kalmbach et al. (2025) Kalmbach D.A., Ong J.C., Cheng P., Reffi A.N., Swanson L.M., Hirata M., Seymour G.M., Castelan-Cuamatzi A.S., Jennings M.B., Pitts D.S., Roth A., Roth T., & Drake C.L. (2025). A randomized controlled trial of telemedicine CBTI and PUMAS for prenatal insomnia: Reducing nocturnal cognitive arousal is a treatment mechanism for alleviating insomnia and depression during pregnancy. Sleep Medicine, 133, 106570. 

Disclaimer

The content in our blog articles is not intended to substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your health provider with any questions you may have regarding your mental health.