Post-TBI Hypersomnia: When Excessive Sleep Isn’t Restorative August 29, 2025 Traumatic brain injury (TBI) is one of the leading causes of death and long-term disability worldwide, affecting around 69 million people every year.1 In Australia alone, an estimated 190,000–200,000 cases occur annually, with roughly 20,000 of these considered moderate to severe.2 For many survivors, the journey doesn’t end once the immediate injury is managed. Instead, lingering effects—such as profound changes in sleep—can significantly impact recovery and daily life.3 Why Does Hypersomnia Happen After TBI? One of the most common yet least understood sleep issues following TBI is hypersomnia: excessive sleep or daytime sleepiness when a person should be awake.4 While sleep is vital for brain healing, post-TBI hypersomnia often leaves survivors feeling unrefreshed, fatigued, and disconnected from life around them.4 Sleepiness and fatigue after brain injury arise from several possible causes. Medications, co-existing sleep disorders like sleep apnea, and pain disrupting night-time rest can all play a role.3 But often, the injury itself is the culprit. Damage to areas of the brain that regulate sleep—particularly the hypothalamus—can disrupt normal sleep-wake cycles.3 Research has found that levels of hypocretin-1, a brain chemical that helps keep us awake and alert, are abnormally low in most patients with acute moderate to severe TBI.3 This mirrors what is seen in narcolepsy and may help explain why many survivors sleep excessively yet never feel fully rested.3 How Common Is It? Excessive sleepiness is more than just an occasional nap. One month after a traumatic injury, more than half of people with TBI report significant daytime sleepiness compared with only 3% of those without trauma.3 Although symptoms often improve with time, about one in four survivors still experience hypersomnia a year later.3 In fact, hypersomnia accounts for about 30% of all sleep disturbances after TBI.4 Those affected often also report fatigue, headaches, irritability, slowed thinking, and difficulties with memory or speech.4 Is All That Sleep Normal—or a Problem? The short answer is yes—it’s normal to need more sleep after a head injury. The brain uses about 20% of the body’s total energy at baseline, and this demand increases dramatically during recovery.5 Rest gives the brain a chance to repair and conserve energy, both of which are essential for healing.5 However, when excessive sleep persists and leaves someone feeling constantly tired, it may indicate post-traumatic hypersomnia. This is different from restorative rest: even after long nights of sleep, survivors may wake up groggy, anxious, or unable to concentrate. Could It Actually Be Sleep Apnea? Not all excessive sleep after TBI is simply hypersomnia. Head trauma has been shown to increase the likelihood of developing sleep-disordered breathing, particularly obstructive sleep apnea (OSA).5 In OSA, the airway repeatedly narrows or collapses during sleep, causing pauses in breathing, fragmented rest, and significant daytime fatigue. Because the symptoms of hypersomnia and sleep apnea overlap—such as excessive tiredness, poor concentration, and unrefreshing sleep—OSA can sometimes go unnoticed in TBI survivors. This makes it important to rule out sleep apnea through tests like a sleep study, especially since untreated OSA can worsen cognitive function, mood, and even cardiovascular health. Why Does It Matter? Sleep is a cornerstone of rehabilitation. Quality rest helps the brain relearn tasks, improves memory, boosts attention, and restores energy.5 But hypersomnia—or undiagnosed sleep apnea—can interfere with rehab by sapping vitality and making it harder to engage in physical therapy, social activities, or even everyday routines. Over time, this can reduce quality of life and slow recovery.3 The Bottom Line If you or a loved one are struggling with overwhelming sleepiness after a brain injury, you’re not alone—and it’s not something to ignore. Keeping track of your sleep patterns and symptoms can help guide conversations with your doctor. Treatments may include lifestyle changes or in some cases, medications. Recovery after TBI is hard enough without exhaustion holding you back. If hypersomnia or sleep apnea is disrupting your healing, talk to your doctor—restorative, refreshing sleep is possible. How Sove CPAP Clinic Can Help Founded in 2008, Sove CPAP Clinic has grown to become a leading provider of respiratory and sleep services and products in Australia, with over 60 clinics nationwide. Our comprehensive clinical team includes Respiratory & Sleep Specialists, Sleep Technologists, and CPAP Consultants, ensuring that you receive comprehensive and personalised care. All medical procedures, including sleep studies and lung function testing, are bulk billed to all Australians, with minimal wait time. If you would like to speak to a Respiratory & Sleep Physician, book a bulk-billed sleep study, or seek advice for your sleep apnea, you can reach us at 1300 76 29 39 or info@thecpapclinic.com.au. ALWAYS FOLLOW THE DIRECTIONS FOR USE. CPAP is used for Obstructive Sleep Apnea treatment. When considering whether a sleep study or CPAP is right for you, speak to your doctor. Medicare criteria and T&Cs apply. References O’Reilly, Gerard M., et al. “The Australian Traumatic Brain Injury National Data (ATBIND) Project: A Mixed Methods Study Protocol.” Medical Journal of Australia, vol. 217, no. 7, 22 Aug. 2022, mja.com.au. Fitzgerald, Melinda, et al. “AUS-TBI: The Australian Health Informatics Approach to Predict Outcomes and Monitor Intervention Efficacy after Moderate-To-Severe Traumatic Brain Injury.” Neurotrauma Reports, vol. 3, no. 1, 1 June 2022, pp. 217–223, ncbi.nlm.nih.gov, doi.org. Watson, Nathaniel F, et al. “Hypersomnia Following Traumatic Brain Injury.” Journal of Clinical Sleep Medicine, vol. 3, no. 4, 15 June 2007, p. 363, pmc.ncbi.nlm.nih.gov. “Sleep Disturbance - Connectivity.” Connectivity, 4 Apr. 2023, connectivity.org.au. Tran, Andrew. “Post-Traumatic Hypersomnia: Understanding Excessive Sleeping after Head Injury - Home Recovery for Stroke, Brain Injury and More.” Flint Rehab, 8 Apr. 2022, flintrehab.com. Accessed 29 Aug. 2025.
