They Say They Have No Energy — So Why Are They So Oversensitive?
The short answer
A child is worn out, yet reacts strongly to small things. You would think that when strength drains away they would go quiet, but instead they get louder. This place, where reactions grow larger as reserves shrink, is something Korean medicine has long had a name for, and modern pharmacology has a name for it too.
Contents
"My child has no energy at all. And yet they get so touchy about the smallest things."
These two remarks often come out together in a single sentence. And then it is added: "That doesn't add up, does it."
It is natural that it sounds like it does not add up. If strength drains away, you would think reactions would shrink too. But there are times when the body does not do that.
Reactions sometimes grow larger as reserves shrink
Sounds grate more than usual, the label on the clothes is said to dig in, smells are hard to bear, and coming back from a crowded place is especially exhausting. And meanwhile there is no energy.
Being weakened and being oversensitive come together. It is not that one of the two is real and the other false — it is a state in which both are present.
The body already has a name for this
There is a name pharmacology uses for this place.
When the signal a nerve sends grows smaller, the cell on the receiving side increases the places that receive it. Since the sound coming in has gotten quieter, it is a matter of enlarging the ear. Then even a small signal produces a large reaction. This is called receptor upregulation. For the phenomenon in which a place cut off from nerve input reacts far more strongly to the stimulus that remains, there is a separate name: denervation supersensitivity.
The weakened side does not go quiet — it gets loud. This is not an exceptional event but a way the body often works.
Korean medicine has held this picture for a long time
In Korean medicine there is a phrase, heo-jeuk-hang (虛則亢). It means that when it is empty it flares up instead. The expression that when the ground dries out, fire rises, points to the same place.
No energy yet shallow sleep, worn out yet startled by small things, no strength yet a pounding heart — this combination, written down in the old medical texts, still comes into the consulting room exactly as it is.
This picture is the kind that is hard for anyone to hold. It requires putting being weakened and being oversensitive in the same place. Korean medicine has long had the words to hold it, and modern pharmacology has put its own name to it. I find the place where these two meet interesting.
With children it usually starts with sleep
Among the routes by which this state is made in a child, the one you can get your hands on is sleep.
That the threshold for feeling pain drops when sleep is short has been measured in people. And something more worth noting was confirmed along with it. The body's own function of dampening pain grows weaker itself. The stimulus is the same, but the side that dampens it loses its power.
When cram-school schedules and late nights are layered on top of this, the child goes through each day with their reserves shaved down a little more. Then the same sound, the same clothes, the same classroom come at them larger than before. It is closer to not that the child has become difficult, but that the power to dampen has decreased.
What I look at in the consulting room
I do not go toward getting rid of the sensitivity. Pressing something down to make it quiet, and reserves returning so that it reacts less on its own, are different things.
I ask how long it takes to fall asleep, whether they wake in the night, how long after getting up in the morning they get hungry, and at what time of day they fall apart. Which side got shaved down first differs from child to child, so even when the same story is brought in, the place I work on differs.
There is one thing I always say to parents. Having no energy while being oversensitive is not something that fails to add up. Nor is the child doing it on purpose.
When to see a doctor first
If they are losing weight, or hurting enough to wake from sleep, or running a fever that lasts a long time, or have suddenly become unable to do what they used to do — it is better to be seen first, before having this conversation. The same goes for being sleepy during the day to the point of not being able to bear it.
This piece is about what to look at in between, when the tests have turned up nothing in particular and yet the child stays in that state.
If what worries you more is the child not getting up in the morning, I have written that down separately in No Matter How I Wake Him, He Can't Get Up in the Morning. At this age the body's clock genuinely shifts later.
Sources
- A study measured in people showing that a single night without sleep makes one more sensitive to pain, and that the body's own function of dampening pain falls along with it — PLOS ONE, 2019
- A review summarizing that when sleep is short the side that suppresses pain weakens while the side that heightens sensitivity becomes active — Neuropsychopharmacology, 2019
Written by Dr. Heo Ji-young (Ph.D. in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)
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