The sympathetic nervous system is an important part of the autonomic nervous system, which regulates the body functions you don't consciously control, such as heart rate, blood pressure and breathing. It's often described as the system that gets your body ready for action, in other words the "fight or flight" response. When you face a stressful situation (whether it's physical, emotional or mental), the sympathetic nervous system switches on right away to help you respond.
In this article we look at how the sympathetic nervous system works, what it does to your body, the possible risks of an overactive sympathetic system, and how to keep a healthy balance.
How does the sympathetic nervous system work?
When you're faced with stress, your sympathetic nervous system sets off a chain of processes in your body that prepare you to react quickly. It does this by sending signals to different organs through your spinal cord and specific nerves. Among other things, the sympathetic nervous system tells your adrenal glands to release adrenaline and noradrenaline. These substances make you more alert, speed up your heart rate and deepen your breathing.
The "fight or flight" response is there to prepare your body for two basic reactions: fighting or running away. Imagine you're suddenly facing a threat, like a car coming straight at you. Within a split second, your sympathetic nervous system makes sure your muscles get more blood, your heart pumps faster and your senses get sharper, so you can react fast.
The main functions of the sympathetic nervous system
The sympathetic nervous system plays a part in several physical processes that get your body ready for action. Here are its main functions:
- Speeding up your heart rate: your heart beats faster to pump more oxygen-rich blood to your muscles, so you're ready to act quickly.
- Faster breathing: by speeding up your breathing, you take in more oxygen, which gives your muscles energy.
- Releasing energy: the sympathetic nervous system gets your liver to release glucose, which gives your body energy it can use right away.
- More alertness: your senses sharpen and you react faster.
- Putting non-essential functions on hold: functions such as digestion and urine production slow down, so all your energy can go to your vital organs and muscles.
What an overactive sympathetic nervous system does to you
The sympathetic nervous system is vital in emergencies, but when it's overactive it can harm your health in the long run. When your body is constantly in "fight or flight" mode, it can lead to chronic stress, tiredness and even health problems such as:
- High blood pressure: constant tension in your blood vessels pushes your blood pressure up, which raises the risk of heart and vascular disease.
- Poorer digestion: long-term stress and reduced blood flow to your gut are linked to digestive problems such as stomach complaints or irritable bowel syndrome (IBS).
- Disturbed sleep: a constantly raised heart rate and fast breathing can make it hard to wind down, which can cause insomnia.
- A weaker immune system: ongoing stress wears out your immune system, which makes you more likely to get sick.
Sympathetic vs. parasympathetic nervous system
The sympathetic and parasympathetic nervous systems work together like the gas pedal and the brake in your body. While the sympathetic system revs your body up, the parasympathetic nervous system helps you calm down again. That balance is super important for a healthy body and a healthy mind.
An overactive sympathetic nervous system can lead to stress-related conditions such as anxiety, depression and chronic pain. On the other hand, an overly active parasympathetic system can lead to extreme tiredness and low energy. That's why finding the right balance between these two systems is so important.
Tips
Want to restore the balance between your sympathetic and parasympathetic nervous systems? Here are some useful tips:
- Breathing exercises and meditation: breathing consciously, for example with the 4-7-8 breathing technique, can lower your sympathetic activity and activate your parasympathetic nervous system.
- Regular exercise: moving helps regulate your nervous system. Choose calm forms of exercise such as yoga or walking to boost your parasympathetic activity.
- Mouth tape while you sleep: just as with the parasympathetic nervous system, mouth tape can help you breathe through your nose, which lowers sympathetic activity. Nasal breathing is calmer and deeper, which makes it easier for your body to relax.
- Enough sleep: rest is crucial for your nervous system to recover. Keep a regular sleep schedule and good sleep habits so your body gets the rest it needs.
Frequently asked questions about the sympathetic nervous system
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What's the difference between the sympathetic and parasympathetic nervous systems?
The sympathetic nervous system revs your body up in stressful situations (the fight or flight response), while the parasympathetic nervous system helps you relax and recover (the rest and digest response). -
What happens if the sympathetic nervous system is constantly active?
A sympathetic nervous system that's always switched on can lead to chronic stress, high blood pressure, digestive problems and a weaker immune system. -
How can I calm my sympathetic nervous system?
Deep breathing, meditation, yoga and wearing mouth tape while you sleep can help calm your sympathetic system and help you relax.
Final thoughts
The sympathetic nervous system is essential: it lets your body react quickly in dangerous or stressful situations. But when it's active too often or for too long, it can lead to health problems. By consciously making time for relaxation and rest, you can bring your sympathetic nervous system back into balance with your parasympathetic nervous system and support your health.
