What You Need to Know About the Autonomic Nervous System (and How to Keep It Healthy)

Colorful illustration of human brain with synapses represented in the background

There are certain parts of the body we have no control over.

We don’t consciously think about breathing or making sure our heart’s beating; our body takes care of that on its own.

The autonomic nervous system is what regulates of all the automatic functions you need to survive. This includes:

  • Digestion
  • Heart rate
  • Blood pressure
  • Breathing
  • Body temperature
  • Metabolism

Doctor giving knee reflex test to patient

Your autonomic nervous system isn’t something you can consciously control under normal circumstances. You can’t force your stomach to digest food faster, or strong-arm your blood pressure until it lowers.

These essential survival functions are so automatic that you probably don’t even think about them.

But the problems that can arise when the autonomic nervous system isn’t working properly can have a very noticeable effect on your life. By taking the time to understand how it works and what can go wrong, you can take steps to realign the system and improve your overall health.

How Does the Autonomic Nervous System Work?

The autonomic nervous system consists of three parts:

  • Sympathetic. Controls the ‘fight-or-flight’ response. This is what activates to help you prepare for potentially dangerous situations.
  • Parasympathetic. The sympathetic system’s counterpart. This helps you calm down after a tense situation, and helps regulate normal, everyday functions.
  • Enteric. A part of the autonomic nervous system that focuses on the gastrointestinal tract.

The first two parts of the autonomic nervous system—sympathetic and parasympathetic—work together to keep your body in balance. While the sympathetic nervous system will speed up heart rate, the parasympathetic will slow it down. The sympathetic nervous system will dilate the pupils, while the parasympathetic will constrict them. By contrasting each other, they help keep us in a state of balance.

Daughter snuck up behind her mom and scared her on the couchThe autonomic nervous system works by taking in outside stimuli and regulating the body to react accordingly.

For example, if you see something large and imposing, your sympathetic nervous system will take over. Once that perceived threat is gone (or you realize it isn’t dangerous) your parasympathetic nervous system will calm you down again.

An Unruly Nervous System

While most of the time our two nervous systems are in sync, sometimes chronic stress can cause us to be “stuck” in a constant state of low-grade fight-or-flight.

When this happens, we may feel generally anxious, have trouble sleeping, and even struggle with depression. The “stuck” feeling is actually because our sympathetic nervous system has become dominant, and so we become less resilient to stress because our relaxation “muscle” (i.e., the parasympathetic nervous system) has become weak. .

Say, for example, you are in a stressful time in your life, perhaps because of a difficult family or work situation, or more commonly, you’re juggling several stressors. The more stress you experience, and the longer it lasts, the more stress hormones your body produces. Eventually, your body’s ability to regulate stress hormones becomes dysregulated.

In addition to anxiety and insomnia, an overactive sympathetic nervous system can cause a number of other problems, such as poor digestion, constipation, shallow breathing, heart palpitations, decreased libido, fatigue, irritability, muscle tension, inflammation, and increased susceptibility to infections.

When your nervous systems are out of balance, activities that should be simple can suddenly become a chore.

Controlling the Autonomic Nervous System

So how do you change something you can’t normally control?

There are, surprisingly, several techniques you can use, and a good place to start is your breathing. Taking a deep breath and holding it stimulates your vagus nerve, which can activate your parasympathetic nervous system and help you calm down.

Relaxation plays a key role in managing the autonomic nervous system. By taking time to “rest and digest,” you can influence your nervous system in surprising ways. Here are a few strategies you can use at home:

Woman in yoga studio focusing on deep breathing exercises

  • Reduce stress. This probably seems a bit redundant, but it bears repeating. Identify the biggest stressors in your life. If you can cut them, do so. If you can’t, look at what you can do to make them less intimidating. (For example, using logic to help rationalize fears.)
  • Practice meditation. Meditation helps center your mind and body, and can get you out of the everyday hustle and bustle. By controlling your breathing and calming your thoughts, you can help stimulate your parasympathetic nervous system.
  • Practice yoga. Much like meditation, yoga is used as a method of relaxation. It can be used to lower heart rate and even (with enough practice) alter body temperature.
  • Get a massage. Massages are—you guessed it—something that many people use to reduce stress. They help relax and remove tension from your muscles. The physical relaxation stimulates mental relaxation, and can help you learn how to relax on your own, even afterwards.
  • Eat a healthy diet. There’s some merit to the old saying, “You are what you eat.” Different foods affect our bodies in different ways. For example, caffeine stimulates the body, so you probably don’t want a lot of it when you’re trying to calm down. Other foods—like chamomile, salmon, and even dark chocolate—can help lower feelings of stress and anxiety.
  • Exercise. This may seem a little counterproductive—shouldn’t physical activity activate the sympathetic nervous system? The key here is moderation. A little bit of exercise—such as a light jog—can actually help you relax. Moreover, exercise releases endorphins that reduce stress and help increase positive feelings.

By finding ways to relax, and returning to a state of calm, you can regain control of your nervous system.

A Well-Working System for a Well-Working You

The autonomic nervous system is an amazing part of the body that keeps us going without conscious input. It’s something we don’t really appreciate until it gets out of control.

An overactive sympathetic nervous system can lead to a number of problems, both physically and mentally. However, with the right methods, you can calm yourself and return to a balanced state.

So take a deep breath, relax and let your autonomic nervous system do its job.