About Circadian Rhythm

Circadian rhythms are the physical, mental, and behavioral changes that follow a daily cycle. It is a roughly 24-hour cycle in the physiological processes of living beings, including animals, fungi, cyanobacteria, plants, etc. In some cases, circadian rhythms are endogenously generated. And those can be modulated by external cues like temperature and sunlight. These circadian rhythms are important in determining the sleeping and feeding patterns of all animals as well as human beings. It is a natural and internal system which is designed to regulate the feelings of sleepiness and wakefulness over a 24-hour period. 

These are the pattern of brain wave activity, cell regeneration, hormone production, and some other biological activities happen in this 24-hour cycle. The circadian rhythm is very important to determine sleeping patterns such as when we sleep or when we wale in every 24 hours. And the normal circadian clock is set by the light-dark cycle over 24 hours. Circadian rhythms are found in living things including plants, human beings, animals, and other tiny microbes. The study of circadian rhythm is called Chronobiology.


Natural factors that occur in the body produce our circadian rhythms. The signals from the environment also affect them. The main reason which influences the circadian rhythm is daylight. This daylight can turn on or turn off genes that control the molecular structure of biological clocks. Altering the light-dark cycles can speed up, or slow down, or reset the biological clocks as well as circadian rhythms. The circadian rhythm may influence sleep-wake cycles, eating habits, body temperature, digestion, hormone release, and all other important functions which happen in the body. Irregularity in the circadian rhythm has been associated with various chronic health conditions such as obesity, depression, bipolar disorder, diabetes, and seasonal affective disorder.

The relation between circadian rhythms sleep

Circadian rhythms determine the sleep patterns of our body. Master clock of the body controls the production of melatonin, i.e. a hormone which makes you sleepy. It receives the information about incoming light from the optic nerves which relay information from the eyes to the brain. When there is less light i.e. at night, the SCN tells the brain to make more melatonin so that you get drowsy. The circadian rhythm works best when you have a regular sleep habits like going to bed at night and waking up in the morning at the same time daily. 


Here are some tips to keep the circadian rhythm in control;

Stick to a consistent sleep schedule  

A regular sleeping schedule is one of the important parts of this process. Waking up at the same time daily will help you to keep your circadian rhythm in check. It may be tempting to grab some further information on weekends, but the same will throw your body off throughout the week. 

Go for a Morning Walk  

At early morning time, exposure to the sun gives you the energy that it can also reset your circadian rhythm. Morning walk gives you enough sun exposure to your brain and boost up to start the day. 

Limit evening Tech  

Bright light in the evening hours can throw your body off. Artificial blue light, the type emitted from laptops, cell phones, and tablets is the not at all good for your health. So, avoid using these devices at least two to three hours before going to bed. 

Some common Circadian Rhythm Disorders 

Rapid Time Zone Change Syndrome 

This disease consists of symptoms which include excessive sleepiness and a lack of alertness in the day time in people who travel across time zones. 

Sleep work sleep disorder 

It affects people who frequently work at night or rotate their shifts.

Delayed sleep phase syndrome (DSPS) 

This disorder is for those people who are affected with DSPS tend to fall asleep very late at night and have difficulty waking up in morning at time for work, collage, school, or some social engagements.

Advanced Sleep Phase Syndrome (ASPD)  

This is a type of syndrome in which a person goes to sleep earlier and wakes earlier than desired. It results some symptoms like going to bed earlier, sleepiness, and waking up earlier than desired. 

Non 24-hour Sleep Wake Disorder 

This disorder affects those people who are totally blind since the circadian clock is set. In non 24-hour seep wake disorder, the cycle is disturbed. This syndrome results in reduced sleep time and sleep quality at night.

What causes Circadian Rhythm Disorders?

There are various factors by which Circadian rhythm disorder can be caused. These are as follow;

  • Time zone changes
  • Medications
  • Menopause
  • Medical problems including Alzheimer’s or Parkinson disease
  • Mental health problems
  • Pregnancy
  • Changes in routine such as staying up late or sleeping in