You’re in a convenience store, examining a can of Spam in one of the aisles. Suddenly a hooded man bursts through the door, pulls out a .45, and waves it in the cashier’s face demanding the contents of the cash register. You begin breathing shallowly, from the chest, as fear for you own life pervades you. Thoughts pinball through your mind: Will he shoot the cashier—and then me? Am I to die in a convenience store of all places? Where are the police?

The cashier complies; the robber bolts through the door. Your breathing slows and deepens and the thoughts in your mind slow. You become calm.

This scenario illustrates the connection between breathing and the mind: Breathe shallowly and quickly, and your mind generates a frenzy of thoughts. Breathe deeply, from the abdomen, and the thoughts slow and become manageable.

What has happened when you perceived danger was your body reacted with the fight-or-flight response—it’s kicked in the sympathetic nervous system, one of the two components of the autonomic nervous system. Your body floods with adrenaline from your adrenal glands as you prepare to confront the threat to your life.

As the threat passes you breathe deeply and the parasympathetic nervous system becomes engaged: heart rate slows, blood pressure returns to normal, adrenal glands stop pumping adrenaline into your system. Normality—you are calm and your body can return to normal operations, such as digestion.

The fight-or-flight response is vital for short-term situations—such as when our distant ancestors confronted deadly threats from saber-tooth tigers and immense short-snout bears. But if you are confronting a serious disease or condition, such as cancer or PTSD, your fear will trigger this response continuously, flooding your body with adrenaline and other chemicals such as cortisol. The effect? Your body cannot heal properly, as these substances compromise the immune system.

The solution? Learn to breathe deeply, expanding your abdomen and filling the lungs from the bottom up. You not only kick in the parasympathic nervous system but also provide much more oxygen to the blood, helping your immune system to operate at a high level.

And there’s another tremendous benefit from abdominal breathing: The lymphatic system, which relies on respiration and muscular action to work (it has no pump, such as the heart pumping the blood), will work much more efficiently. The lymphatic system contains vital elements of the immune system, such as the bone marrow—the blood factory—and the thymus gland, which kicks out T-cells, the body’s natural killer cells which destroy cancer and other invaders.

The lymphatic system does many things, such as producing lymphocytes that fight disease and removing toxins from the cells. If you are fighting cancer or another serious condition or disease, abdominal breathing is a crucial element in helping you win your fight.

I learned deep, abdominal breathing as the first step in my practice of qigong (chee-gung, which means energy work—Chinese internal energy exercises). It is also a vital component in other meditative and energy arts such as yoga, tai chi chuan and transcendental meditation.

You can learn abdominal breathing by expanding your abdomen as you breathe, focusing on filling the lungs with air from the bottom up. A good way to test if you’re doing it correctly is to lie on the floor and place a box of Kleenex on your stomach. As you breathe, the box will rise and fall with the motion of your stomach.

If you are fighting cancer, as I have many times years ago, you may be too tired from chemotherapy and/or radiation to do standing or moving qigong, tai chi chuan or yoga. But you can always lie down and breathe deeply, and still stimulate your immune system. It worked for me: four bouts of bone cancer, two bone marrow transplants between 1991 and 1996—and I’ve been clear ever since. Fifteen years of good health. I can’t catch a cold.

Bob Ellal