The highly sensitive nervous system detects more information and uses more brain resources to process it.
Imagine a dense forest — above you, a canopy of branches filters streams of sunlight. At your eye level, where the light falls, shrubs thrive. Below, on the ground, more foliage flourishes in the shade, with the thick bases of large tree roots and thin, slithering vines climbing around trunks, curling around branches, and spilling over from above. You see the richness of life around you and stand in speechless awe at the realization that this luxuriance is just a tiny patch in a vast, unruly forest.
Now imagine that all the leaves, branches, stems, and roots of the numerous plants and trees around you are talking to each other. According to the BBC documentary The Green Planet, narrated by Sir David Attenborough, they do just that. When one leaf is bitten, it sends distress signals, telling other leaves to curl up in defense or flood themselves with bitterness. When nutrients are found by one inquisitive root, they are directed not only to that plant but shared with others around them. In essence, the forest communicates within itself.
As I watched The Green Planet, I was reminded of a connection that scientists made as early as the 19th century. I found it fascinating that, crouched over their microscopes studying neurons, researchers were reminded of trees. They called the branches of nerves “dendrites,” a word that literally means “like trees.”
Like the forest, the body also communicates within itself. One of the ways it does so is through nerves. When something pokes or scalds a tiny bit of skin, nerves tell muscles to contract, causing the entire limb or body to curl away from danger.
In addition to nerves and their ability to communicate, our nervous systems have something that, to our knowledge, forests do not have: a center where signals from the expansive terrain are brought and sorted, where plans are made, and from where orders are sent out. This hub of nerves and impulses is what we call the brain.
The network of nerves extending across the body and forming the brain is particularly special in highly sensitive people (HSPs). Before we examine how the HSP nervous system is different, let’s first understand how the human nervous system typically works.
(Are you a highly sensitive person? Here are 27 “strange” things highly sensitive people do.)
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How the Nervous System Works
Research indicates that nerves extend throughout the body, capturing cues from both the body and the environment and transmitting them to the brain. Some nerves exist entirely within the brain, connecting different parts and allowing them to communicate with each other. These nerves call up memories hidden in secret libraries of the mind, reason within themselves, and plan the best course of action. Other nerves take those decisions to the rest of the body, informing each part what to do.
Our nervous systems are extraordinarily complex and maintain intricate relationships with every other system in the body. In highly sensitive individuals, the nervous system is even more receptive and responsive.
The highly sensitive nervous system is attuned at every level. It perceives more information, allocates more resources to processing information in the brain, and causes the body to respond in a more sensitive manner. Let’s take a closer look at the ways in which we are more sensitive than others.
Anatomy of a Highly Sensitive Person
The Nervous System
Research suggests that sensitive people pick up more signals from both within the body and the environment than others do. These signals also tend to be more intense. Additionally, studies indicate that sensitive people are slower at tuning out their surroundings.
I imagine it like a microphone that’s very sensitive to ambient sounds. It detects and captures several sounds while filtering out very few. Sometimes, being a highly sensitive person feels like listening to an audio clip with a lot of irrelevant background noise.
While our sensitive nervous systems pick up more from the environment, this makes our lives beautiful in many ways. Sensitive people experience the world more vividly, quickly spotting differences and appreciating nuances, as Jenn Granneman explains in her book Sensitive. We pick up subtleties in the body language of those around us, which helps us be understanding and empathetic.
However, noticing so much can also have drawbacks. It’s a lot of information to juggle, and our nervous systems are forced to always be on alert. Additionally, noticing tiny details means we may be easily bothered by imperfections, asymmetry, and inconsistencies. We may be deeply disturbed when what people say doesn’t match their body language.
The Brain
If our nervous systems pick up many impulses, it also means more impulses reach our brains. The brains of highly sensitive people are constantly dealing with data, even at rest. Additionally, functional MRI and EEG research shows that the highly sensitive brain uses more of itself when processing information compared to the brain of a less sensitive person. It’s almost as if the sensitive brain brings in more consultants before making a decision. Researchers refer to this extensive brain engagement as “depth of processing.”
Sensitive people are deep thinkers by nature. We spend considerable energy and time weighing things in our minds before acting on them. Since more information is brought to the brain, more information also reaches our consciousness. As a result, sensitive people are also consciously thinking — and worrying — about many things.
The Body
Considering that our nerves reach every inch of our bodies and affect every system, it is not surprising that our bodies are sensitive, too. Studies have shown that sensitive people feel more stress and experience more symptoms of illness than others. Chronic stress, in turn, has long-lasting negative effects on the body and mind. Sensitive people also react more strongly to stress and trauma. They burn out more easily when stressed and are more likely to develop PTSD, anxiety, or depression in response to trauma.
Physical illnesses — like gut disease, migraines, and type 1 diabetes — are also associated with sensory processing sensitivity. Studies also suggest that sensitive people may experience more allergies than less-sensitive people. However, the mechanisms and extent of this increased sensitivity need more research.
This is not to say that sensitive people like us are always sick or fragile. We are usually healthy individuals who can accomplish anything we set our minds to. However, the research warns us of the potential consequences of neglecting our sensitivity and taking our bodies and minds for granted.
Is the chaos of life overwhelming you as a highly sensitive person?
Sensitive people have certain brain differences that make them more susceptible to stress and anxiety. Thankfully, there is a way to train your brain so you can navigate the challenges of sensitivity, access your gifts, and thrive in life. Psychotherapist and sensitivity expert Julie Bjelland will show you how in her popular online course, HSP Brain Training. As an Introvert, Dear reader, you can take 50% off the registration fee using the code INTROVERTDEAR. Click here to learn more.
How to Better Care for Your Sensitive Self
We are people with sensitive systems, and our ability to notice more and think more deeply adds value to the world. According to Dr. Elaine Aron, author of The Highly Sensitive Person, we are wise advisors, inspired artists, and pensive philosophers. However, due to how our bodies and minds work, we require some extra care. Here are two things you can do to better take care of your sensitive self:
1. Curate your experiences.
Because sensitive people take in a lot of information, our experiences — whether positive or negative — can easily become overwhelming. To prevent feeling on edge, pick and choose the activities you engage in. This may seem strange to others, as many of the things we avoid are often considered exciting.
For example, many of us don’t like parties because we know the environment might be too stimulating: The music could be loud, the lights too bright or flashy, and the personalities varied. We may also be extra sensitive to alcohol, smoke, or certain foods. So we might pass on the party. This isn’t because we dislike people or are killjoys; parties just may not be our thing.
Many highly sensitive people also dislike surprises. We’re accustomed to tuning into others through their body language, interests, and words, and we expect others, including those less sensitive, to do the same for us. This can lead to disappointment when a surprise turns out to be overstimulating or a letdown. Most of us are happy to participate in surprises if allowed to choose our own gifts or activities. While it’s not technically a surprise anymore, you may find us surprisingly pleased.
Most sensitive people also don’t enjoy being frightened. Horror, gore, and thrillers can haunt us for several nights, causing us to worry about the people in the stories and how we’d respond in similar situations. This can be very unpleasant, leading many sensitive folks to avoid these genres altogether.
The desire that we sensitive people have to regulate our experiences is often misunderstood. We may be seen as boring, serious, or uptight. However, we’re not trying to be any of these things; we’re simply trying to stay sane and avoid overstimulation.
2. Rest whenever you need it, even in small doses.
Processing information, even subconsciously, takes energy. Think of how a long trip, even a fun one, might leave you feeling achy all over. This is what happens in sensitive people’s brains. After a good amount of stimulation — whether at the end of the day, upon completing a task, or returning from a vacation — we may feel exhausted. What we need is rest (yes, even after the vacation!).
I’m reminded of my vacuum cleaner. It’s an odd thing: After working for 10 to 20 minutes, it gets very hot and won’t work anymore. After an hour of bewildering stillness, it revs back to life and sucks things up from its environment again, as though nothing had happened.
Sensitive people are sort of like that: After periods of intense stimulation, we need downtime. Without the rest we need, we don’t function at our best. We might space out and get silent or become prickly and snappy with everyone around us. However, after some rest — even through micro-recharging — we will once again be the perceptive, sensitive souls you know.
We tend to take the rest we need by withdrawing from the world, spending time by ourselves, doing mundane things that don’t require much brainpower, and by sleeping. It’s not that we’re lazy; we’re just trying to reset our systems.
Sensitive Systems Need to Be Handled With Care
The sensitive experience is widely misunderstood. Many people associate sensitivity with political correctness or believe it to be a collection of unsorted phobias or trauma. Some think we have an unjustifiable attitude of entitlement, while others label us as “aloof” or “snobbish.”
It’s true that we may be conscientious, cautious, and particular. But really, we’re just people with highly responsive nervous systems trying to flourish in a vast, competitive, and overstimulating world. From experience, we’ve learned that our sensitive systems need to be handled with care. We know that we have high-maintenance bodies and brains, and we’re simply doing our best to take care of ourselves. 
