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Circadian Rhythm and Sleep

After 22 years as an RN, I now write about medical issues and new medical advances. Diet, exercise, treatment, and lifestyle are important.

Sleep Facts

Sleep has been difficult for me without some sleeping aide for the past decade, primarily due to nerve pain. I use a sound machine with the sound of rain, which seems to help, and a prescribed medication. I sleep about 6.5 hours nightly, which is usually enough.

Healthy adults require between 7-9 hours of sleep each night. Healthy children and teens need hours of more sleep. Some older people like one of our fellow Hubbers, Bill Holland, report they sleep extremely sound, but he may be the exception.

A study in the USA reports that women get more total sleep nightly, but their sleep is typically fragmented, so they have a lower quality of sleep. Women have 3-5 cycles nightly lasting from to 70-120 minutes, which depends on age. They tend to have more time in the third stage. However, sleep is dependent on a great number of factors, and it varies from one person to another. Lack of sleep may cause cognitive impairment.

Children with developmental or psychological disorders have a 70% risk of developing a sleep disorder. Even children have sleep disorders, which are not well understood by researchers.

Sleep Stages

The 4 stages of sleep for men and women include:

  • Stage 1 - Lightest sleep non-rapid eye movement, which is also called quiet sleep
  • Stage 2 - Rapid eye movement (REM), called paradoxical sleep, lasts about 20 minutes
  • Stage 3 - deepest sleep, muscles relax, heart rate and blood pressure lower (NREM)
  • Stage 4 - the body usually returns to REM sleep

Sleep cycles tend to last from 70-120 minutes per night and occur from 3-5 times each night. REM sleep is where dreams occur, and you are immobilized, plus your eye movement is rapid.

Somewhere between 30-40 years of age our sleeping patterns often change. Approximately 5-25% of our total sleep is associated with dreaming. The non-REM sleep is divided into 4 categories of increasing depth. The deepest sleep occurs in the early part of the night.

Stages of Sleep - non-REM, REM, Sleep Studies

Circadian Rhythm - Lark Or Owl?

Our circadian rhythm is generated by our internal biological clock. If you do your best work in the morning you are a lark, but if you are a night person you are an owl. Older adults typically have more difficulty going to sleep, staying asleep and then remaining alert throughout the day. Research has found that older adults have weaker electrical activity in the brain.

Animals also have a circadian rhythm, which tells them when to prepare for a change in their environment.

I guess I am a lark, but I don’t know if I was born that way. I worked for some decades as an RN and started work at 6:45 a.m. most days, but when I stopped working I continued to wake up early. I am now classified with the advanced sleep phase syndrome (ASPS).

People with ASPS typically wake up between 3:00 to 5:00 a.m., so they like to go to bed between 7:00 and 9:00 p.m. When a person with ASPS has family and social obligations, they cannot always get to bed so early. Therefore, they often suffer from sleep deprivation.

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The other extreme is referred to as delayed sleep phase syndrome (DSPS). Individuals with DSPS often go to bed after 2:00 a.m., and they have a difficult time waking up before 9:00 to 10:00 a.m. They often have difficulty with work or school obligations. If the person happens to awake earlier, they still have trouble going to sleep any earlier.

Are You a Lark or an Owl?

Your circadian rhythm may run slightly more or or slightly shorter than 24 hours. We each have different needs to meet our sleep requirements. Our circadian rhythm is thought to be generated by genetics. The rhythm tells us when to sleep, eat and wake. Travel and shift work can negatively affect this rhythm.

Other factors that impact the circadian rhythm include:

  • Sleep disorders
  • Obesity
  • Diabetes
  • Depression
  • Bipolar disorder
  • Hypersomnia - a neurological disorder where excessive time is spent sleeping
  • Schizophrenia - nightmares, sleep walking, sleep talking and poor quality of sleep

Researchers have established that a person’s circadian rhythm is influenced by their exposure to light.

Other Factors That Impact Sleep

Underlying biology includes hormone production, sleep cycles and circadian rhythm. In addition, there are gender-based factors that are connected to cultural and social disparities. These disparities are multifaceted and overlapping, and they begin in puberty with hormone production. The sex-based factors continue to evolve over time with aging.

The transition as we age may be abrupt as older people usually feel as if they are a lighter sleeper than when they were younger. Older people often spend less time in dreamless, deep sleep, but they wake up from 3 to 4 times nightly. They are more aware of being awake because they spend less time in deep sleep.

Additional factors include:

  • Caffeine
  • Alcohol
  • Some Medications
  • Anxiety
  • Sleep apnea
  • Restless leg syndrome
  • Needing to get up and urinate (nocturia)
  • Long-term chronic pain or illness
  • Major depressive disorder (MDD) - insomnia has a threefold increased risk of developing MDD
  • Allergic reaction over produce histamine that may cause an allergic reaction that inhibits sleep
  • Narcolepsy is a neurological condition that is characterized by daytime sleepiness, Hallucinations at sleep onset, cataplexy (a sudden paralysis) and disturbed nighttime sleep.

Sleep disorders (somnipathy) are medical disorders of the sleep patterns. These sleep disorders can be serious enough to interfere with normal physical, social, mental and emotional functioning.


How To Improve Your Sleep

Try to keep the same schedule each day. Seek out the sunlight each morning as exposing yourself to the sunlight and the darkness helps to support melatonin production.

Marked daytime sleepiness is unhealthy and can be dangerous. Chronic insomnia and sleep-related behavioral problems may be diagnosed by a sleep disorder specialist. There is testing available for some sleep disorders.

Treatments for insomnia generally fall into 4 different categories that include:

  1. Behavioral and psychotherapeutic treatment with a mental health specialist
  2. Rehabilitation and management therapy is based on personal interaction with a health care specialist.
  3. Medications - There are numerous types of medication, in addition to melatonin.
  4. Other somatic treatments are available when there is no known medical cause for insomnia and the patient is very concerned about their symptoms.

Sleep Myths | Fact or Fiction with Dr. Ilene Rosen

In Conclusion

There are numerous causes of insomnia. Our circadian rhythm may explain the problem, or it could be any number of other causative factors. There are a variety of treatments, and just eliminating caffeine or alcohol may sometimes solve the problem.

Sleeping Habits


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2021 Pamela Oglesby


Pamela Oglesby (author) from Sunny Florida on February 03, 2021:

Hi Ankita,

I am glad you found the article informative. Thank you for your comments as they are much appreciated. Take care.

Ankita B on February 03, 2021:

It was interesting to read about the different stages of sleep. Very informative article. Thank you for sharing.

Pamela Oglesby (author) from Sunny Florida on February 03, 2021:

Hi John,

I wake early every day and don't need an alarm ether. I'm sorry to hear about you wife. My sister's husband uses the CPAP machine also.

I appreciate your comments, John. I hope you are having a good week.

John Hansen from Gondwana Land on February 02, 2021:

A great article Pamela. I only get about six or seven hours of sleep per night but when I doze off I sleep soundly. I never need an alarm clock though because I always wake up in time for anything I need to prepare for. My wife has sleep apnoea however and has to sleep with a CPAP machine.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Shauna,

I love those little tricks we all use to get enough sleep. Your method is so simple, and I may try it.

I appreciate you sharing your method as it works for you. Thank you for sharing. Have a wonderful rest of the week!

Shauna L Bowling from Central Florida on February 02, 2021:

Pamela, I found this article quite enlightening. I sleep pretty well, but usually awaken around 3:00 a.m. to go to the bathroom. I've developed a trick over the years to allow me to go right back to sleep: I walk to the bathroom (en suite) with my eyes squinted so they're barely open and do the same back to my bed. It seems I pick up where I left off with no trouble or tiredness when I finally awaken for the day.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Devika,

I think many people share your way of going to sleep later, and that is healthy as long as you get enough reat.

I appreciate you dropping by and commenting. I hope you are healthy and doing well. Take care.

Devika Primić from Dubrovnik, Croatia on February 02, 2021:

Pamela99 Information such as this is important and you share facts and great work. I find sleeping early iss not for me and prefer sleeping later to not lie in bed and not fall asleep.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Manatita,

I am glad you now have the luxury os lying in bed as nurses we sure didn't lie in bed for long. It is nice to hear of the Brahma Murhuta. I Bible, meditate or pray with only a dim light. I love being up with no on else, no TV or radio first thing.

I am glad you found the article to be informative. Thank you so much for your comments, as always. Stay safe and healthy, Manatita.

manatita44 from london on February 02, 2021:

I don't always sleep well, Pamela and I'm usually tired a.m, so I just lie in bed a bit longer. I may doze off or not. I take essential amino acids, which are supposed to help. Not noticeable.

A great article and well explained. The Brahma Murhuta (The hour of God), is usually the time when nature is at its quietest (0300 - 0400 hrs). Yogi's and some Buddhists monks rise at that time to meditate. I use to do this also. Rarely now.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Chitrangada,

I think you are right, and I imagine the pandemic has affected people also. I know age has affected my sleep patterns, and I am also a lark. Worry certainly affects the sleep of many people too.

I appreciate your comments,as always. I hope you are having a very good week.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi MG,

I'm glad you found this article to bre informative. Your very kind comments almost make me blush, but they are always appreciated. Hope you are having a great week.

Chitrangada Sharan from New Delhi, India on February 02, 2021:

Very informative article about sleep and it’s various patterns.

I believe, our sleep patterns change according to age and situations. If something is worrying me, my sleep is badly affected. Otherwise, I have a sound sleep. By your categorisation, I believe, I am lark. Early to bed, and early to rise.

Thank you for sharing this wonderful information. I learnt a lot from this.

MG Singh emge from Singapore on February 02, 2021:

Pamela, this is a very informative article and as usual you show that you have mastery over the subject.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Linda,

I love that picture too. I am glad you found the article educational. I appreciate your comments. Have a good week, Linda.

Pamela Oglesby (author) from Sunny Florida on February 02, 2021:

Hi Flourish,

I don't think it is terribly unusual to have changed the way you sleep. At least you get your 8 hours. You may change again as you age. The pandemic has impacted most of us in some way.

Thank you so much for your comments. Take care.

Linda Crampton from British Columbia, Canada on February 01, 2021:

This is another interesting and educational article, Pamela. I love the photo of the sleeping koala!

FlourishAnyway from USA on February 01, 2021:

Your new photo is beautiful! Such a pretty, positive smile.

Most of my life I've naturally been a night owl, but when my daughter was in high school she was in an engineering high school and had to catch a 5:55 a.m. bus so I turned into an early riser out of necessity. My routine persisted even after she graduated (she's in her last year of college). Now, however, I've evolved into this odd pattern of sleeping a total of about 8 hours but doing it in halves. I go to bed at midnight, get up at 4:15 a.m. with the cats, stay up for about 4 hours then sleep another four hours. With an empty nest and now the pandemic, no one complains.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

I think you are on the right track, Ann. I believe biorhythms and our body-clock impact how we feel and think, impacting everything we do. More research on this topic would be fascinating. Thank you, Ann.

Ann Carr from SW England on February 01, 2021:

It's all to do with biorhythms and the body-clock, apparently!


Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Ann,

I imagine your research on the time of day to work or exercise was interesting. I find the topic fascinating also.

I use to sleep like a log when I was young, but those days are long gone.

This pandemic has gone on for such a long time. I think it is quite understandable that sleep patterns or dreams have been affected. It is sure possible, but I suppose we will not know for sure until it is over.

I am glad you found the article to be well-explained. I always hope I am putting forth new, good information for everyone.

I appreciate your comments, Ann. Have a wonderful week.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Rosina,

I'm glad your sleeping problem is handled. I take a pill also as pain wakes me up otherwise.

I am glad you also found the article informative and interesting. Thank you so much for your coments. Have a wonderful week, Rosina!

Ann Carr from SW England on February 01, 2021:

Very interesting, Pamela. Glad I got here in time to comment easily!

I did some research on this some time back, when I was teaching. I also came across data on what times of day we work better, or exercise better, etc. I find it fascinating.

I used to sleep like a log but these days I often get up and sometimes have to go downstairs and read a little or do a crossword until I feel like sleep again. I also think it has something to do with the current situation and worrying. Strangely, I have more dreams lately, which had tailed off over many years, except if I'm away somewhere - very odd! Again, I think worry over Covid is upsetting my brain! That's probably quite common, do you think?

Anyway, you've produced another well explained and detailed article which is a pleasure to read, Pamela. Thank you.


Rosina S Khan on February 01, 2021:

I had problems with sleep years ago and I have been since taking a sleeping pill which helps me to sleep well until the morning and doesn't make me drowsy either.

I have to agree with Peggy that I found this article informative and interesting too. Like Dora said I want to read again and study it. Thank you for sharing, Pamela.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Peggy,

I am glad you found the article informative and interesting, We do change as we age.

Have a wonderful week., Peggy!

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Linda,

Your sleep pattern sounds just like me. A sickly baby would interfere with sleep. I appreciate your comments.

Have a wonderful week, Linda!

Peggy Woods from Houston, Texas on February 01, 2021:

Our sleep habits definitely change as we age. Your article about circadian rhythms was informative and interesting.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Clive,

I am glad you found this article interesting. I appreciate your comments. Have a great week!

Linda Lum from Washington State, USA on February 01, 2021:

I'm a lark; I wish I could sleep past 6 am, but the kitty will have none of it. I think my sleep pattern changed when I became a mom with a sickly baby. She's an adult now but I still sleep light and hear every sound in the house

Clive Williams from Jamaica on February 01, 2021:

Very Informative and Interesting

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Ms Dora,

When we wake up during the night I don't think it is very easy to know what stage we were in, except we problem wouldn't naturally wake up during deep sleep.

I have been awakened by someone and felt very groggy, so I guess that would be a deep sleep time. I hope I made sense in this comment.

I am glad you found this article to be interesting. I appreciate your comments. Have a wonderful week, Dora!

Dora Weithers from The Caribbean on February 01, 2021:

I'm definitely a lark. I've read this through, but I have to reread and study. The information is very interesting especially the section on sleep stages.Thanks.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Linda,

I am glad to hear you have no sleeping problems. Thank you for reading and commenting. Have a great week!

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Ruby,

There are not many advantages to allergies, but you antihistamine sounds like one. Sleeping medicine can make you drowsy in the a.m., so I drink coffee. LOL

I appreciate your comments, and I hop you have a good week.

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Bill,

I remember you mentioning you were a sound sleeper, so I hope you didn't mind me mentioning you in this article.

I hope the article helps Bev, but she may be a but like me and that is difficult. Thanks so much for commenting. I hope you have a wonderfel week too!

Linda Chechar from Arizona on February 01, 2021:

I do sleep every night. The sleep cycles and circadian rhythm!

Ruby Jean Richert from Southern Illinois on February 01, 2021:

This was another interesting article. I am a lark. I sleep well. I have allergies so I take an antihistamine at bed time and it makes me sleep. I worked for a Doctor who would only give it for sleep. He explained that a sleeping pill left one drowsy in the morning. Thanks again for sharing.

Bill Holland from Olympia, WA on February 01, 2021:

Great information, my friend. I am a sound sleeper. Bev is up roaming the house most nights for an hour or so. I will give her this article to read. Perhaps it will help her.

Have a wonderful week!

Pamela Oglesby (author) from Sunny Florida on February 01, 2021:

Hi Heidi,

I use to work swing shifts at the hospital, and it was really difficult. I certainly agree that work schedules are an issue.

Thank you for reading and for your nice comments. Have a great week!

Heidi Thorne from Chicago Area on February 01, 2021:

Work schedules play a huge role in sleep, too. Hubs has a 4am wake up which is really difficult. I couldn't do it! Great review of sleep issues and cycles!

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