Do you experience abnormal sleep patterns that often leaves you wondering how it happened? Apparently, there’s a sleep disorder that causes your body clock to be all messy! Let’s talk about it here.
Non-24-Hour Sleep-Wake Syndrome refers to the unstable sleep pattern caused by a dysfunctional, internal body clock that cannot follow the normal light-dark sleep pattern.
What is the Non-24-Hour Sleep-Wake Syndrome?
The Non-24-Hour Sleep-Wake Syndrome is one of the several chronic circadian rhythm sleep disorders (CRSDs).
Here’s how it affects you.
For example, today you slept at 10 PM. Tomorrow, you may end up sleeping at 11 PM and eventually you may go to sleep at 3 AM and then next, 8 AM.
You are unable to follow a proper sleep pattern because your internal body clock is not working well.
The difference in time can be unnoticeable but sometimes the difference can become too great for it to be ignored.
For more details, this syndrome often occurs in blind people but sighted people can also be affected for several reasons.
Our internal body clock responds to light and when there is no longer light, your body will automatically know that it is time to “sleep” but people with non-24 hour sleep-wake syndrome may struggle with this.
You can also somehow say that their internal body clock is unable to have a “sense of time”.
Every animal and plant have an endogenously generated near-24-hour “circadian” clock rhythm, the real term for “internal body clock”
The circadian clock rhythm’s job is to regulate the normal 24-hour cycle of biological processes like sleeping or hormone production. The rhythms have a period close to but not exactly 24 hours.
They are synchronized daily by environmental time cues which is, for us mammals, day light.
For mammals, the circadian rhythms are generated by the hypothalamus, a term you’ve probably read or heard about in biology class or so.
The hypothalamus is also called “suprachiasmatic nuclei (SCN)” which is a structure inside our brain that follows the regular “day and night” cycle which is why most mammals sleep and wake during similar times.
The ability to sleep at night and be awake at day is deeply controlled by the internal body clock which is generated by the hypothalamus.
Since the hypothalamus makes you sleep at night and wake in morning, you are going to follow that set clock. When the night comes, your hypothalamus knows that it’s time to “reset” the clock and go to sleep.
This is why blind people are more prone to Non-24-Hour Sleep-Wake Syndrome than sighted people as they do not have the vision to see daylight and let their internal body clock know it’s time to reset.
But still, sighted people can be affected by non-24-hour sleep-wake syndrome and some blind people can still have normal sleep routine.
To make it simpler, in a sense, the hypothalamus is like the “written codes” and the circadian rhythm is the “program” that runs with it. Like how old versions of clock run with cogs or so.
The Non-24-Hour Sleep-Wake Syndrome prevents your hypothalamus from working or from perceiving daylight as waking time and night as cue for sleeping.
This syndrome causes people to not be synchronized with the normal 24 hour rhythm set by the internal body clock.
Imagine your computer changing “timezone” each time you turn it off and on. It never stays close to the “default” timezone, making your sleep routine complicated.
One day or week, you sleep normally during the night but then all of a sudden, you couldn’t sleep no matter what and stayed past your regular bedtime… eventually causing you to sleep in the day instead.
This will go on until the Non-24-Hour Sleep-Wake Syndrome is dealt with. It will become an endless cycle of irregular sleep patterns which is not good for your health.
Types of Non-24-Hour Sleep-Wake Syndrome
Although the majority of people with the Non-24-Hour Sleep-Wake Syndrome are blind people, it also occurs in a small number of sighted people, making it two types of the syndrome.
Blind
Most blind people do have certain level of light perception, meaning, they are still able to synchronize their internal body clock with the normal 24-hour day-night cycle that most people follow, like sighted people.
Still, it has been shown that approximately half of all the population of blind people do not have light perception. Totally blind people are at the most prone to the Non-24-Hour Sleep-Wake syndrome.
However, this condition can happen to anyone at any age.
Normally, the syndrome occurs shortly after loss or removal of the patient’s eyes because the photosensitive ganglion cells in the retina are also removed.
In other words, Non-24-Hour Sleep-Wake Syndrome is common in totally blind people due to a lack of light entering their eyes.
Without light to the retina, the hypothalamus will not be able to perceive when it is time to sleep and wake, making it dysfunctional and now falls into the Non-24-Hour Sleep-Wake Syndrome.
Apparently, studies reveal that even when a person goes blind or is born blind, as long as their light perception remains in the retina no matter how strong they can perceive light they can be safe from the syndrome.
Researchers mentioned that even the slightest amount of light exposure at night can affect the body clock.
Sighted
Non-24-Hour Sleep-Wake Syndrome among sighted people is still continuously being studied, but is commonly believed to be caused by neurological disorders.
Here are some of the potential reasons why the syndrome may occur among sighted people.
- Changes in the environment
- Temperature changes, different daylight hours in different seasons or other factors
- Traveling to a different time zone
- Adapting to a different time zone may take awhile to become effective for some, causing them to be affected by the non-24-hour sleep-wake syndrome
- Stress levels
- Stress and other emotional, mental health problems can potentially cause disruption in sleep pattern and also keep the person away from day light.
- Doing activities late at night
- Being a “night owl” or someone simply busy at night can also affect the body’s internal clock
- Shifting job schedules
- Just like traveling to different time zones, difference in time will make it hard for your internal body clock to adjust and set your sleep pattern back to normal
- Illness such as fever
- When people are sick, they tend to stay in and also feel the need to relax for the day, not seeing day light as much as they should and also losing control of their sleeping routine
- Sleep deprivation
- Pulling an al-nighter too frequently on purpose will eventually disrupt your sleep pattern or simply depriving yourself of sleep will force your body to disobey its natural internal body clock
- Fatigue
- Being tired will cause your body to save energy, forcing it to not follow the normal sleep routine set by your internal body clock
- Medications
- Sedatives that can relax the muscles to the point of becoming drowsy or sleepy can also disrupt our sleep pattern
- Isolation
- There are sighted people that actually prefer to stay inside their homes all day, every day. They’re humorously called “shut-ins” but they also refer to themselves as “introverts”.
These people that choose not to see the light of the day will also cause their internal body clock to become dysfunctional.
- There are sighted people that actually prefer to stay inside their homes all day, every day. They’re humorously called “shut-ins” but they also refer to themselves as “introverts”.
The syndrome can also occur to any sighted person of any age, even childhood. Sometimes it is preceded by delayed sleep phase disorders.
Diagnosis
The Non-24-Hour Sleep-Wake Syndrome is diagnosed when the patient fails to follow a 24-hour light-dark cycle and clock times.
A diagnosis of non-24-hour sleep-wake disorder requires the documentation of progressive shifting of the sleep-wake times over at least 14 days using sleep diaries and / or actigraphy.
Actigraphy is highly similar to a “polysomnography“, or a sleep study, but is a lot easier and less expensive.
You are only required to wear a device, usually small ones like a wrist watch that can monitor your body’s activities throughout the day until you go to sleep and you will wear it for a certain period of time.
An assessment of a strong biochemical circadian rhythm, such as the melatonin or cortisol rhythm, can confirm whether a non-24-hour rhythm is absent or present.
This can be obtained or observed through actigraphy.
In sighted people, the diagnosis is typically made based on a history of persistently delayed sleep onset that follows a non-24-hour pattern.
The disorder can be considered very likely in a totally blind person with periodic insomnia and daytime sleepiness, although other causes for these common symptoms still need to be determined properly.
(Related: “How to Do a Sleep Study?”)
Symptoms
Though the symptoms may be quite noticeable, to some it may only slowly become noticeable if their sleeping pattern goes back to normal for a period of time and goes back to the unnatural non-24-hour sleep-wake syndrome.
- Hypersomnolence
- Excessive daytime sleepiness
- Insomnia
- Inability to sleep at night
- Persistent delayed sleep
- Constant delayed sleep is a symptom of the non-24-hour sleep-wake syndrome
When these common symptoms are experienced both or all together at once, it means the person is most likely affected by the non-24-hour sleep-wake syndrome.
(Related: “Hypersomnia“)
Risks
Even though this syndrome does not seem threatening, consistent irregular sleep pattern can later hurt your overall health. So what are the complications that can possibly happen?
Aside from the risk of sleep deprivation, the most common problem with this syndrome is that it deeply affects their performance or ability to function in their daily lives.
School, work or social lives are all affected by this syndrome.
Trying to keep up with majority of the world’s natural time results in insomnia or hypersomnia since the person with the syndrome forces themselves to stay awake in a time that their body clock doesn’t follow.
Usually, it is sighted people that force themselves to follow the normal body clock of everyone else, disobeying their own, dysfunctional body clock affected by non-24-hour sleep-wake syndrome.
Sometimes it results in excessive sleepiness, feeling tired all the time, headache, changes in appetite and mood problems.
It’s because the overall body is affected when sleep is involved.
The syndrome also often causes late attendances or absences. Even when the affected person is present, their mind are usually asleep since it is not supposed to be “awake” during that time.
Treatment
- Tasimelton
- Tasimelton effectively treats blind patients as an alternative for melatonin. It works the way melatonin should, which is regulating your body temperature and more.
Since tasimelton successfully and safely regulates your body, it helps keep your circadian rhythm synchronized with the natural light and dark cycle.
- Tasimelton effectively treats blind patients as an alternative for melatonin. It works the way melatonin should, which is regulating your body temperature and more.
- Melatonin
- Melatonin is a hormone that helps your body know when it’s time to sleep and wake up. By following the melatonin therapy, you improve your body’s ability to sleep.
It will stay in tune with the natural circadian rhythm, keeping you healthy and free of other complications caused by the non-24-hour sleep-wake syndrome.
- Melatonin is a hormone that helps your body know when it’s time to sleep and wake up. By following the melatonin therapy, you improve your body’s ability to sleep.
- Light and Dark Therapy
- This therapy involves using light exposure to act against the circadian rhythms and prevent it from being delayed.
Light also suppresses melatonin secretion, so it makes the melatonin inside your body stay longer than usual, causing to regulate your sleeping hormones much longer.
Currently, this way of therapy is not fully mastered so it is not available as an option unless needed for extreme or desperate measures.
- This therapy involves using light exposure to act against the circadian rhythms and prevent it from being delayed.
Related Questions
What is it called when you sleep during the day but not at night?
Sleeping during the day and not at night is a common symptom of narcolepsy and other neurological disorders that affect your control of sleep and wakefulness.
Usually, patients with narcolepsy experience excessive daytime sleepiness or hypersomnolence.
But then again, there are other possibilities which requires adequate examination to properly determine the cause behind an unnatural sleep routine.
Is it bad to sleep all day and stay up all night?
Yes, sleeping all day and staying up all night is actually not good for your health especially because our body normally processes biological changes such as hormone production while we sleep at night.
Our body follows a normal internal clock that we must follow, otherwise, the “system” inside our body may become dysfunctional. The natural body clock knows that daytime is for waking and night is for sleeping.
There is a great difference between sleeping in the day and sleeping at night, your body becomes healthier when you sleep at night.
Why am I tired all day but not at night?
It is possible to feel tired all day due to restless sleeps at night. Restless sleeps can be caused by a variety of sleep disorders or other illnesses that may be affecting the quality of your sleep.
A possible disorder that you may be experiencing is the non-24-hour sleep-wake syndrome, wherein your body clock is set differently than usual causing you to feel inactive during normal waking hours.
