Surreal illustration representing hidden sleep disorders.

Unmasking Hidden Sleep Issues: When It's Not 'Just' Sleep Apnea

Beau Callahan in Health & Wellness December 2025 • 4 min read.

"Beyond the Usual Suspects: Exploring Uncommon Sleep Disorders and Effective Solutions for Better Rest"

Feeling tired even after a full night's sleep? You're not alone. While obstructive sleep apnea (OSA) is a common culprit, excessive daytime sleepiness can have surprising underlying causes. Understanding these hidden factors is the first step toward reclaiming your energy and well-being.

This article dives into recent research that sheds light on less common sleep disorders that can mimic or mask themselves as other conditions. We'll explore how these conditions are diagnosed and, most importantly, how targeted treatments can make a significant difference.

Whether you're a parent concerned about a child's sleepiness, someone experiencing unexplained fatigue, or simply curious about the complexities of sleep, this guide offers valuable insights and actionable information.

Case 1: Trisomy 21 and Narcolepsy – A Double Whammy for Sleep

Surreal illustration representing hidden sleep disorders.

Trisomy 21 (Down syndrome) is associated with an increased risk of obstructive sleep apnea due to factors like obesity and hypotonia (decreased muscle tone). However, sleepiness in individuals with Trisomy 21 isn't always solely due to OSA. Other sleep disorders can co-exist and worsen symptoms.

A recent case highlights this point perfectly: a 13-year-old with Trisomy 21 presented with snoring, possible apnea, and excessive daytime sleepiness. Initial assumptions might point to OSA, but further investigation revealed a more complex picture.

A sleep study (polysomnogram) showed only mild obstructive sleep apnea.
A multiple sleep latency test (MSLT) revealed a mean sleep latency of 4 minutes and 37 seconds, with three sleep-onset REM periods – indicating narcolepsy.
Genetic testing confirmed the presence of HLA DQB1 06:02, further supporting the narcolepsy diagnosis.

This case emphasizes the importance of thorough evaluation, even when a condition like Trisomy 21 is present. The patient was diagnosed with both mild obstructive sleep apnea and narcolepsy without cataplexy. Treatment with positional therapy and modafinil (a medication to promote wakefulness) led to a dramatic improvement in daytime sleepiness, school performance, and physical activity levels. The Epworth Sleepiness Scale score decreased to 8 after treatment, indicating a significant reduction in sleepiness.

Don't Settle for 'Just Tired': The Importance of Comprehensive Sleep Evaluation

These cases demonstrate that daytime sleepiness can be a complex issue with multiple potential causes. It's crucial to look beyond the obvious and consider less common conditions like narcolepsy and NPH.

If you or someone you know is experiencing persistent daytime sleepiness, don't dismiss it as 'just being tired.' Talk to your doctor about a comprehensive sleep evaluation to identify the underlying cause and receive appropriate treatment.

By understanding the diverse range of sleep disorders and seeking expert evaluation, you can pave the way for better sleep, improved health, and a more energized life.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

What are some of the underlying causes of daytime sleepiness, besides Obstructive Sleep Apnea?

Daytime sleepiness can be caused by more than just Obstructive Sleep Apnea (OSA). While OSA is a common cause, other conditions like narcolepsy and normal pressure hydrocephalus (NPH) can also lead to excessive daytime sleepiness. It is crucial to consider these less common conditions because they require different treatments than OSA. Understanding these hidden factors is the first step toward reclaiming your energy and well-being.

What is Narcolepsy and how is it relevant to the discussion of sleep disorders?

Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness, often accompanied by other symptoms such as cataplexy (sudden loss of muscle tone). In the context of sleep disorders, as highlighted in the case involving Trisomy 21, narcolepsy can coexist with other conditions like obstructive sleep apnea (OSA). The diagnosis of narcolepsy involves a comprehensive evaluation, including a sleep study (polysomnogram) and a multiple sleep latency test (MSLT).

What is the purpose of the multiple sleep latency test (MSLT) in diagnosing sleep disorders?

The multiple sleep latency test (MSLT) measures how quickly a person falls asleep during the day and whether they enter rapid eye movement (REM) sleep. The MSLT result, such as a mean sleep latency of 4 minutes and 37 seconds with three sleep-onset REM periods, is indicative of Narcolepsy. This test is important in diagnosing conditions like narcolepsy, where excessive daytime sleepiness is a primary symptom. The test helps differentiate between various sleep disorders and guides treatment decisions.

How does Trisomy 21 relate to sleep disorders?

Trisomy 21 (Down syndrome) is associated with an increased risk of obstructive sleep apnea (OSA). Individuals with Trisomy 21 can have multiple sleep disorders. The article provided a case study of a 13-year-old with Trisomy 21 presented with snoring, possible apnea, and excessive daytime sleepiness. The initial assumption may point to OSA, but further investigation revealed a more complex picture. This emphasizes the importance of comprehensive sleep evaluations.

Why is thorough sleep evaluation important?

Thorough sleep evaluation involves a comprehensive assessment to identify the underlying causes of daytime sleepiness. This process may include sleep studies, such as a polysomnogram and a multiple sleep latency test (MSLT), as well as other diagnostic tests. The importance lies in identifying the correct diagnosis so that targeted treatments can be administered. In cases where conditions like Narcolepsy are identified, treatments such as positional therapy and medications like modafinil can significantly improve symptoms and overall quality of life.