Have you ever had a day when you were exhausted and wanted nothing more than to take a nap? Most people have experienced this feeling at one time or another. However, for those living with central disorders of hypersomnolence (CDoH), this feeling of extreme sleepiness is constant, regardless of how long they have slept.
CDoH is a group of neurological sleep disorders characterized primarily by excessive daytime sleepiness (EDS) that persists even after adequate nighttime sleep has occurred. In these disorders, EDS is unrelenting and often interferes with a person’s daily life. This significantly impacts their work, education, relationships, and their quality of life.
Narcolepsy
One of the most recognized CDoHs, narcolepsy, comes in two forms. Narcolepsy Type 1 (NT1) is the better-known type and is characterized by EDS, disrupted nighttime sleep, and cataplexy, which are sudden episodes of muscle weakness that are triggered by strong emotions like laughter or excitement. People with NT1 may also experience sleep paralysis and vivid hallucinations as they fall asleep or wake up. Narcolepsy Type 2 (NT2) shares many of the same characteristics as NT1, including severe daytime sleepiness and disturbed nighttime sleep, but it lacks cataplexy.
“Living with narcolepsy requires a constant balancing of priorities against my symptoms,” shares Matthew Horsnell, who lives with narcolepsy. “Excessive daytime sleepiness, cataplexy, and brain fog require a combination of treatment approaches. For me, successful management requires medication, naps, social support, and lifestyle adjustments. My diagnosis and proactive management help me be the best version of myself, albeit a sleepy version most days.” Like many others, he’s found that a diagnosis and the right support system can make a meaningful difference, even if symptoms persist.
Idiopathic hypersomnia
Idiopathic hypersomnia (IH) is a disorder that causes overwhelming, excessive daytime sleepiness, even when people have had sufficient or even prolonged nighttime sleep. They often struggle with sleep inertia, a heavy, foggy feeling that makes waking up extremely difficult. Unlike with narcolepsy, naps are often unrefreshing.
As Diana Kimmel, who lives with IH, explains, “Having IH means I can wake up exhausted after sleeping 10+ hours, left to decide what I can do with the little amount of wakefulness I have. It’s not that I don’t want to do things, but rather that IH has its own plan for my day. Often it leaves me yearning for a nap that won’t be refreshing.” For many, even being awake can feel physically painful, and treatments are often limited or ineffective.
Kleine-Levin syndrome
Kleine-Levin Syndrome (KLS) is a rare disorder, primarily affecting adolescents and young adults, characterized by recurring episodes of extreme EDS. During these episodes, individuals sleep excessively, often 15 to 20 or more hours a day. They also experience behavioral and cognitive disturbances, such as confusion, irritability, hyperphagia (excessive eating), and hypersexuality. Episodes can last days to weeks and may recur unpredictably over months or years.
“One of the scariest things about living with KLS is that you never know when another episode is going to hit and completely stop your life,” shares Arielle Poleg, who was diagnosed with KLS. “As a teenager and 20-something, I suffered 23 episodes of KLS, during which I slept for up to 23 hours a day for weeks or months at a time. I missed school, holidays, proms, sports seasons, friends’ weddings, and even my grandfather’s funeral. I was trapped in bed while my own life was whizzing by. There are no words to describe what it feels like to not know if you are awake or asleep, in a dream, or even alive.”
Life with a central disorder of hypersomnia: more than just sleepy
Living with a CDoH means constantly managing an invisible and often misunderstood condition. For many, the daily struggle goes beyond just feeling sleepy; it is a constant fight to stay awake during conversations, at work, in class, or when spending time with loved ones. The unpredictability of sleep attacks and the social stigma attached to falling asleep at inappropriate times can lead to isolation, depression, and anxiety. Greater awareness and understanding are essential for improving the lives of those affected by these disorders. To learn more, please visit www.sleepconsortium.org.
