Psychosomatics
What Happens in My Body When I'm Stressed?
What the HPA axis, cortisol, and your autonomic nervous system have to do with stomach pain, headaches, and muscle tension.
You know the feeling: before a test, your heart beats faster. Your stomach feels weird. Your hands get sweaty. This doesn't happen randomly. Your body has its own alarm system that kicks in automatically when you're stressed - without you controlling it.
Stress is not imaginary and not a sign of weakness. Stress is a physical reaction with a concrete mechanism. This article explains what actually happens in your body when you're stressed.
The stress axis - your body's own alarm system
When your brain classifies something as threatening - a test, an argument, a new situation - a chain reaction starts. It begins in the hypothalamus, a small area in the brain that passes signals to the pituitary gland (a hormone gland in the brain). The pituitary gland then sends a signal to the adrenal glands (two small glands sitting on top of your kidneys). There, cortisol is released - the most important stress hormone in your body.
This pathway is called the HPA axis - hypothalamic-pituitary-adrenal axis. It is as old as humanity itself and was originally designed to protect you from danger: from a wild animal, a fall, an injury.
The problem: your body doesn't distinguish between a wild animal and a maths test. The reaction is the same.
The following conversations are taken directly from the app - uncut and unedited.
User question
Why does my stomach hurt when I'm scared?
Rehavio (Patient)
When you're scared, your body activates something called the stress response. This is when your brain sends alarm signals through your whole body to prepare for danger.
Your stomach has millions of nerve cells - almost like a second brain. When you feel scared, these nerves react immediately. Your stomach muscles tense up, blood flow changes, and digestion slows down. That's why you might feel butterflies, knots, or actual pain in your stomach.
This connection between feelings and stomach is real biology. The nerves between your brain and gut constantly talk to each other through something called the vagus nerve. This is a big nerve highway that connects your brain directly to your stomach.
The pain you feel isn't "fake" or "just in your head" - it's your body's natural alarm system working. Sometimes this system can become too sensitive, especially if you've been stressed or scared a lot. Then your stomach might hurt even when there's no real danger.
In rehab, we work on calming this alarm system down through breathing exercises, movement, and understanding these body signals better.
This response is from Rehavio. You can ask your own questions - about your situation.
What cortisol does in your body
Cortisol is not inherently bad. In short stress situations, it actually helps you: it makes you more alert, more focused, quicker to react. Your body provides energy, your heartbeat speeds up, your muscles tense.
When the stress is over, the system shuts back down. Cortisol is broken down, the muscles relax, the heartbeat normalises. That's how it's supposed to work.
For many children and teenagers, however, the stress doesn't end after an hour. School pressure, conflicts at home, worries about friendships - these are not single events but ongoing states. And when the HPA axis stays permanently active, things happen in the body:
- Stomach and gut: Cortisol changes blood flow to the digestive organs. The gut muscles cramp or become overactive. The result: stomach pain, nausea, diarrhoea.
- Muscles: Baseline tension rises. Neck, shoulders, and jaw are permanently tense. This leads to headaches and muscle tightness.
- Immune system: Chronically elevated cortisol weakens immune defences. Children under chronic stress get ill more often.
- Sleep: Cortisol is a wakefulness hormone. If it doesn't drop in the evening, you lie awake even though you're tired.
User question
What does stress do to my body?
Rehavio (Patient)
Stress activates your HPA axis - that's the connection between your brain and adrenal glands that releases stress hormones like cortisol and adrenaline. These hormones make your muscles tense up (which can cause headaches or back pain), change how your gut works (leading to stomach aches or nausea), and make you more sensitive to pain.
When stress becomes chronic, this system stays switched on all the time - like an alarm that won't stop ringing. Your immune system gets weaker, making you catch colds more easily. Your pain threshold drops, so normal sensations can feel painful. This is called central sensitization - your nervous system has learned to be on high alert.
The cool thing is: once you understand this mechanism, you can work with it. That's why relaxation techniques, movement, and talking about feelings actually help - they calm down that overactive alarm system.
Ask your own questions - about what's happening in your body.
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Real or imagined?
A question that concerns many children and teenagers: Am I imagining the pain? The answer is clear: No. The stomach pain, headaches, and tension are real physical reactions. They arise through measurable processes - hormone release, muscle tension, altered blood flow. These are not "phantom pains" and not excuses.
What's different: the trigger is not a broken bone or inflammation, but a stress response. But the pain in the body is just as real. Your nervous system makes no distinction between "physically caused" and "stress-related" - the pain feels the same because it travels along the same nerve pathways.
When a doctor says "we can't find anything" it doesn't mean nothing is there. It means the pain is not caused by an injury or inflammation. The cause lies in the stress system - and that doesn't show up on an X-ray.
User question
Is this real or am I imagining it?
Rehavio (Patient)
The pain is real. Psychosomatic pain uses the exact same nerve pathways as pain from an injury - your brain receives genuine pain signals.
When doctors say "we can't find anything," they mean no organ is damaged or inflamed. But that doesn't mean you're imagining it. Your nervous system is sending real pain signals, just like when you hit your knee - except the trigger is stress or emotions instead of physical damage.
Think of it like this: When you blush from embarrassment, the red cheeks are real even though no one slapped you. Your body reacts to emotions with physical changes. With psychosomatic pain, your body reacts to stress or difficult feelings with pain signals.
The pain you feel is as real as any other pain. Your nervous system doesn't distinguish between pain from a broken bone and pain from stress - it processes both through the same pathways. That's why psychosomatic pain hurts just as much.
Many people don't understand this mechanism well, which can make you feel like no one believes you. But the pain is neurophysiologically real - measurable changes happen in your nervous system.
A bright spot
The nervous system of children and teenagers is particularly adaptable. What this means: a stress system that has learned to run on overdrive can also learn to wind back down. In rehab, different therapies work together - movement, relaxation, conversations - to give the body new experiences. Experiences that show: it's possible without the alarm. Your body can process stress without staying permanently on alert. This takes time, but it works.
Rehavio explains chronic conditions in age-appropriate language - what happens in the body, why therapies help, and how rehab works. Whether for yourself, as a parent, or as a professional.
