The human body is an amazing piece of work. It regulates your temperature, heals a cut and keeps the heart beating while you are asleep. It is also downright strange.
Every day, it does things we accept without question—until a sudden, weird moment makes us stop and ask, Why did that just happen?
According to family medicine doctor and Head of the Police Health Facility, Dr Marie-Joanna Francis, many of these quirks are simply the nervous system firing automatic responses to familiar signals and changes. She notes that in Trinidad and Tobago, we also have plenty of colourful, cultural and superstitious explanations, though there is usually a perfectly normal physiological reason behind them.
Here is a look at a few of those moments and the actual science.
Why do you suddenly need to pee when you get home?
You may have been fine for most of the journey. Then you turn onto your street and the urge starts. By the time you reach the front door, you feel like you can’t hold it any longer. Your bladder and brain are in constant communication. The brain learns to link certain places with bathroom trips, so the surroundings themselves become a cue. This is sometimes called latchkey urgency. Your mind registers a familiar situation as a signal that it is safe to let go. Just pulling up to the yard is all it takes.
Why do fingers wrinkle in water?
A long bath can leave your fingertips looking as though they have aged several decades. For years, the common explanation was that the outer layer of skin absorbed water and swelled. That is not the whole story.
The wrinkling involves the autonomic nervous system. Blood vessels beneath the skin constrict, reducing the volume beneath the surface and creating the ridged appearance. Researchers have also investigated whether the effect serves a purpose, like giving wet fingers better channels for moving water away and improving grip. The verdict is still out on that.
Why does seeing someone
yawn make you yawn?
You see a co-worker yawn in the opposite cubicle, and within seconds, your jaw is opening wide. Even reading the word “yawn” right now might already be working on you.
Yawning contagion is a curious psychological and neurological phenomenon that happens to the vast majority of people. Science still hasn’t pinned down a single definitive cause, but leading theories point towards empathy and mirror neurons in the brain. When you observe someone else performing an action, specialised brain cells react as if you were doing it yourself. Researchers opine that in social animals like us it may be a sneaky way to keep the whole group on the same energy page—basically a built-in “everybody stay alert” signal. So no, you aren’t just easily controlled—your brain is wired to mirror the people around you.
Why does your stomach
make noises?
A stomach rumble can be embarrassing in the middle of a meeting, examination or any other quiet moment. The sound does not necessarily mean you are hungry. Your digestive system is moving contents along all the time, using muscular contractions known as peristalsis. Those movements push food, liquid and gas through the stomach and intestines. An empty stomach can make the sounds more noticeable because there is less food to muffle them. The medical term, borborygmi, sounds considerably more serious than the ordinary explanation.
If, however, the noises keep coming with pain, vomiting, bloating or changes in bowel habits, that is worth a chat with your doctor.
Why does your eyelid twitch?
It starts with a tiny flutter that you can feel but sometimes barely see. Then it happens again. And again. Eyelid twitching, or myokymia, is usually harmless and temporary. Tiredness, stress, caffeine and eye strain can all contribute. Most episodes settle without treatment. A twitch that hangs around for weeks, spreads across the face or comes with other unusual symptoms is the one to get checked.
Why does your body jerk
as you fall asleep?
You are almost asleep when your leg abruptly kicks. Or your shoulder jumps. Sometimes the movement comes with the unsettling sensation that you are falling.
These are known as hypnic jerks. They occur as the nervous system moves from wakefulness towards sleep and are common in healthy people. They may be more noticeable when you are overtired, stressed or have consumed stimulants like caffeine. There is no need to panic when your body gives itself a quick jolt at bedtime. For most people, it is part of the transition into sleep.
Why does spicy food
make your nose run?
Pepper sauce tastes delightful, but for some people it can bring tears and a runny nose. The culprit is not necessarily an allergy. Compounds in spicy foods can stimulate nerves in the nasal passages, causing the nose to produce more mucus, resulting in gustatory rhinitis.
Chilli peppers are a common trigger, but other strongly flavoured foods can have the same effect. By all means enjoy your spicy meals, just have an extra napkin handy. Your nose is just responding to what you are eating.
Why do you get goosebumps?
Goosebumps are one of those things that make perfect sense once you know how they work. Tiny muscles attached to hair follicles contract when we are cold or hit by strong emotion. That makes the hairs stand up and creates the familiar bumps. It happens whenever the temperature drops or a song gives you chills.
Why does cold food
cause brain freeze?
There is a good reason that eating ice cream too quickly can make you immediately regret it. A brain freeze occurs when something extremely cold comes into contact with the roof of the mouth. Nerves and blood vessels in the area respond to the sudden temperature change, producing pain that can be felt in the forehead but usually disappears once the stimulus is gone.
Dr Francis says understanding what is normal helps people stay aware of their bodies without panicking over every odd sensation. “When something is persistent, painful, severe or clearly different from your usual pattern,” she says, “that is the moment to ask your doctor. Know your body. And when in doubt, check.”
