Circadian Rhythms and Chinese Medicine

From Sleep to Sleepless

Author: Chad Wuest

I am consistently amazed by how much I see a new research article either verifying, or re-affirming what traditional medicine has been telling us for thousands of years. Recently I read an article on the circadian rhythm, or the “body’s internal clock”, which reminded me of the Diurnal Qi cycle in Traditional Chinese Medicine.

Firstly, an overview of the circadian rhythm in the scientific model for those who aren’t aware.

The two important hormones we should mention here are Serotonin and Melatonin.

What are these hormones? Well….. ever wondered why you feel “energised” in the morning (we are supposed to feel awake without the morning coffee)……well as it turns out, that “awakeness” is related to serotonin. When the sun comes up in the morning, a set of neurons in the Hypothalamus area, specifically the suprachiasmaticus nucleus (SCN), detects light entering the retina (even when the eyes are closed, certain amounts of light penetrates those thin translucent lids)….. neurons get activated…..and just like a coal furnace, it starts “firing up” the production of serotonin. This keeps us alert and feeling good ALL DAY.

It’s not until the sunset edges onto the horizon, that we start to experience the “Melatonin and Serotonin sea saw”.

As the darkness increases, the neurons involved with serotonin become less stimulated, to a point where there is no light (in natural circumstances). This causes a shift…… Where serotonin peaked during the day hours, it has now begun its decent downward into the trough of a melatonin wave, which is now peaking. The melatonin levels begin to rise, increasing the feeling of tiredness, to the point of where we eventually feel SO TIRED…..we fall asleep. This is why using bright computer screens and smartphones at night is such a hot topic at the moment. It directly affects the way serotonin and melatonin work with each other, therefore they affect HOW and WHEN you feel tired or awake.

This system, on a basic level, is what manages the circadian rhythm…’s the “master clock” of the body, streamlining physiological process, creating healthy rhythms of wakefulness and sleepiness. And not only healthy rhythms……healthy feelings!

If your serotonin is balanced, you are feeling good enough to face work and all the ups and downs it brings with a smile on your face.

So what has all this got to do with the Diurnal Qi cycle in Chinese Medicine? 

Well as it turns out…….there are other, “subsets” of clocks……. “Other clocks? What are you talking about?”.

Well, as science would have it. The liver has one, the spleen, even individual cells have a unique “clock” that regulates the timing of how and when organs function metabolically. Thousands of years ago however, Traditional Chinese Medicine already had a system for the ebb and flow of different organs at different times. It looks like this.

Sourced from

The diurnal qi cycle is a system that we learn in our Acupuncture and Chinese Medicine degree. Chinese Medicine has a vast number of theories, such as those that relate to Acupuncture Meridians, Acupuncture Points, Trigger Point Therapy (The activation of twitch responses at tender or painful muscles), How the organs relate to emotions, Herbal medicine and dietetics to name but a few.

One of the theories (the one we are talking about) relates to how the different organs of the body functions at different times of the Day……. the diurnal qi cycle.

So what’s this all about? Well, ever wondered why you feel hungry when you wake up? Well naturally, you should normally feel hungry between 7am and 9am. This is usually when we feel hungry right? Looking at the above picture, in the diurnal qi cycle, 7am – 9am is the natural time of day for the Stomach to be at its optimal function. The reason this is important is because we are more likely to get optimal digestive efficiency at this time. What’s another time of day we are likely to feel a little tired? Lunchtime. Well, according to the clock, 11am – 1pm is heart time. This is a good time to slow down, possibly even have a nap. When we slow down, we give all the blood that is circulating through the limbs and muscles, a chance to focus in on nourishing the heart and getting that quick burst of REM…. The Spanish had it right all along!

But….going back to the scientific modal of the circadian rhythm……even though subsets of clocks, tend to function under the overall master clock system directed by the brain (SCN), they can begin to function independently, effecting the “master” clock. For example, waking at 1am in the morning after sleeping for 3 hours, from the horror movie you watched, which is giving you nightmares, you start to feel hungry and eat….. Do you feel awake now? YES! Well now your stomach is awake and when is its natural peak time? 7am – 9am…. your whole circadian rhythm is beginning to show a split personality disorder!

The TV or mobile phone gives the bright light….. Neurons begin firing up the production of serotonin, which all disrupts your circadian rhythm and makes your melatonin peak delay so that your feeling more drowsy in the daytime instead of night time when you should be going to bed.

So how can we use this information to improve our sleep quality? The main points to take from this are to:

• Gradually decrease your sources of un-natural light once the sun goes down
• Don’t eat really late at night. It disrupts your body clock
• Sleep in a room that is dark, blocking any light coming in through the windows etc.
• Consider decreasing or structuring your TV to earlier shows
• Wake up earlier to get increased light exposure for the production of serotonin
• Eat a good breakfast in the morning to help those other body clocks synchronise with the master clock

Obviously there can be many other factors influencing sleep which sometimes need to be considered, but this is a good start!

So, in returning to the overall picture, we can see evidence is proving right now what the traditional doctors and clinicians were aware of thousands of years ago. This Awareness of subtle physiological processes is not superior to one or another type of medicine, it only emphasises the similarities and my wonderment of both systems.

Both traditional and western medicine have stumbled upon very similar findings, only that it was arrived at using totally different methods.

Chad Wuest

Acupuncture practitioner in Hobart TAS

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