You Are Not Being Chased by a Tiger, but Your Nervous System Thinks You Are

Jennifer O'Sullivan
6 min readFeb 10, 2017


Tiger @ The Dublin Zoo, 1936 — National Library of Ireland on The Commons @ Flickr Commons

Let’s talk about stress. Specifically, I want to tell you what happens in your body when the answer to the question “Am I OK?” is “No.”

Part of your nervous system operates behind the scenes, quietly steering various internal, physiological processes from hormone regulation to heart rate to digestion. It’s in charge of all the things that are going on in your body that you don’t have direct control over.*

The autonomic nervous system, as it’s called, is divided into two parts: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system is what kicks in when you are threatened, and is sometimes referred to as the “Fight or Flight Response.” If you ever found yourself being chased by a tiger, you would have to fight the tiger or get the heck out of there. Quickly.

What the brain tells the body to do when it’s being chased by a tiger makes a lot of sense. Here are some of the things that happen:

  • Adrenaline and cortisol hormones are released.
  • Heart rate and stroke volume increases to quickly move blood through the body.
  • Blood vessels restrict to increase blood pressure, also for quicker blood movement.
  • Blood sugar and blood lipids increase for more energy to move.
  • Shallow, chest breathing increases in order to quickly exchange oxygen and carbon dioxide.
  • Circulation to your gut decreases, because digestion is an energy intensive process that you don’t have time for right now.
  • Immune function increases for about an hour to help block infection from any wounds you might incur, but then it drops off.
  • Reproductive function diminishes because, honestly, it’s not the best time to get busy.

Once you are free from danger, the sympathetic nervous system backs off allowing the parasympathetic nervous system to rebalance your physiological systems.

This makes a lot of sense if you need to defend yourself or run like hell because all these processes enable the body to do some pretty amazing things when it needs to. The problem is that your brain treats all stress as if you are being chased by a tiger. It doesn’t differentiate between your boss calling you to her office in that particular tone of voice and an axe-wielding maniac.

Our lives are inundated with “paper tigers,” those not-life-threatening stressors that we can’t seem to get a break from. Our sympathetic nervous system doesn’t have a low gear, so we end up with chronic effects of stress including high blood pressure, fatigue, depression, poor digestion, ulcers, high blood sugar, decreased fertility, chronic inflammation, and poor immune function, just to name a few. Chronic stress is linked to the top deadliest diseases in America.

By now you may be wondering how to get the parasympathetic nervous system to kick in. The simplest answer is to extract yourself from the circumstances that cause you stress. I highly recommend low-key vacations. Realistically, that’s not always possible. This is where mind-body practices come in.

Let’s go back to the question, “Am I OK?” This is not a conscious conversation that you have with yourself. When it comes to the sympathetic nervous system, you can’t reason with it. This decision-making happens at an unconscious level and draws on input from other systems in the body, including our sensory nervous system: vision, hearing, somatic sensation (touch+), taste, and smell. Information is constantly being transmitted by your sensory organs, even while you are sleeping.

We can use the sensory nervous system to our advantage, and let the sympathetic nervous system know that the answer to the question “Am I Ok?” is “Yes,” in so much as our life is not immediately threatened. This is why spas play relaxing music instead of heavy metal during your massage. Scents like lavender and mint are classic stress reducers. A breathtaking vista does wonders for our well-being. Even tastes, like a perfectly ripe peach, can lower our stress hormones. (Side note: mindless eating can actually compound stress, so be watchful of how you turn to food for relief.)

The best way to really show your sympathetic nervous system who’s boss is through the somatosensory system. Touch is not the only aspect of somatic sensation. In fact our sense of “touch” is actually the largest sensory system in our body. This is because the somatosensory nerves embedded in our ubiquitous connective tissue greatly out number all the other sensory nerves. Not only do they track our soft tissues so our brain can orchestrate the graceful movements humans are known for, but they also provide information on whether or not we are ok.

Besides touch, the somatosensory system includes two other major components: proprioception (awareness of where the body is in space) and interoception (awareness of our internal regulation responses like breathing, heart rate, hunger, etc.). If you practice yoga, tai chi, or any other mindful movement, a light bulb is probably going on right now.

Tai Chi movement chart — Source: Wellcome Library, London

The secret sauce to mindful movement modalities is that not only are you moving the body, which by itself is good for you, but you are doing it in such a way as to enhance proprioception and interoception. When these areas of perception are trained up, we are much more in-tune with our body and internal state, and we are better able to tend to ourselves with appropriate care.

Not all movement is good for stress relief. A soccer player on a team that is tied in a sudden death round is not OK according to his nervous system. The nervous system is thinking, “You’re running like mad. There must be a tiger. Here let me help by pumping you with aggressive hormones and then switch up all your internal systems so you have enough energy to get out of there.” Add to that the pressure of winning and we wonder why the player goes nuts and gets a red card because someone bumps into him. Of course after the game, the nervous system notices that the crisis is over and the parasympathetic nervous kicks in to do its thing to restore harmonious internal functioning.

But if you are a stressed-out, under-slept office worker with a demanding boss, let’s think about whether a vigorous exercise routine is the best thing for you. Chances are you are already full of stress hormones and have poorly performing systems (see list above). Even a vigorous yoga class may be too much for your system. Sure you may sleep better that night after class, but it might be because you are exhausted not because your body is primed to sleep.

Gentle forms of yoga, tai chi, and evening walks with your dog wake up your somatosensory nervous system while also signaling your brain that you’re OK. You would not roll around on the floor in one of my yoga classes or enjoy a sunset walk on the beach if a tornado was coming your way. You really wouldn’t lie down on the floor, spread-eagle, in corpse pose at the end of class if someone was out to get you. So, if you want to use movement to reduce stress, you want to do things that you would never do if you were threatened, and you get bonus points if you participate in activities that encourage you to pay attention to how you feel while you are doing them. Do this regularly.

Below is a 16 minute, gentle yoga sequence that not only reduces tissue tension in your upper back and shoulders, but it also helps to bring your sympathetic nervous system back from the edge.

*Breathing is the exception. We can control our breathing when we want to, but it’s nice that we also don’t have to think about it.

You can join me online every Monday evening at 6 EST/NYC for Yin Yoga & Mindfulness. It’s by donation, and all are welcome.

Hi! I’m Jennifer O’Sullivan (Sati Yoga). I write about yoga, meditation, stress management, Internal Family Systems, functional anatomy, and a bit of this and that about living a wakeful life. Based in the Washington, DC area, I share gentle yoga, Buddhist mindfulness, and facilitated IFS Parts work in person and online. Find me at I also co-host Skillful Means Podcast, which covers spirituality and yoga.



Jennifer O'Sullivan

Shame-free embodied practices, rooted in timeless wisdom. Yoga, Buddhist Mindfulness, Internal Family Systems (IFS)