There is an interesting relationship between Tai Chi and our lymphatic system. The lymphatic system has three primary functions¹ including its role in holding, creating, training, and sending lymphocytes through the body to fight infections. But we are going to focus on how it “returns excess interstitial fluid to the blood”². Interstitial fluid is an essential part of our physiology. It fills the spaces outside of individual cells so it “bathes and surrounds the cells of the body, and provides a means of delivering materials to the cells, intercellular communication, and removal of metabolic waste”³. After being delivered into the tissues, “As the interstitial fluid begins to accumulate, it is picked up and removed by tiny lymphatic vessels and returned to the blood. As soon as the interstitial fluid enters the lymph capillaries, it is called lymph.”⁴

Our lymph needs to get from the tiny lymph capillaries back to the circulatory system driven by the heart. This is particularly important for the lower portion of our body, since gravity works against the lymph moving upward. If the lymphatic system isn’t functioning well, we experience edema, swelling of our bodies due to fluid retention, and perhaps even more importantly it also means our immune system is impaired, since “One of [the lymphatic system’s] major roles is in the coordination of the trafficking of antigen and immune cells.”⁵

The lymphatic system exists throughout our body, as can be seen with this diagram⁶:

Since the lymphatic system doesn’t have a pump like our heart, the lymph is moved differently. Lymph vessels include a series of one-way valves which allow the the lymph to move in only one direction, toward the heart. Movement of lymph occurs through changes in pressure within the tissues which squeeze the lymph vessels. “The pressure gradients to move lymph through the vessels come from the skeletal muscle action, respiratory movement, and contraction of smooth muscle in vessel walls.”⁷

Movement is a key part of moving the lymph, and not unique to Tai Chi. But Tai Chi has certain aspects of movement that contribute notably to circulating our lymph:

1. The arms: the numerous places we bend and straighten our arms helps move lymph up the arms and into the shoulder area.
2. The shoulders: many of our arm movements in Tai Chi alternate opening and closing the shoulder joint in a way that helps work the auxiliary lymph nodes.
3. The knees: bending and straightening our knees helps with moving lymph up the legs, important for avoiding swelling (edema) in our lower bodies.
4. The hips: the regular turning of our torso into and away from each leg, folding and unfolding the k’ua/kuà (inside of the hip)^†, alternately compresses and releases the inguinal lymph nodes and vessels, helping to pump lymph up from the legs and into the torso. This is yet another reason we want to ‘turn the waist’ (the entire torso as a unit) and not twist the spine.
5. Diaphragmatic breathing: the relaxed, slow, full, diaphragmatic breathing we cultivate in Tai Chi creates a pumping effect that moves lymph from the cisterna chyli, a sac near the tan t’ien/dān tián^†, up the torso to the thoracic duct which empties into the circulatory system near the heart. In addition it helps by ”[…] stimulating deep lymphatic structures, such as the cisterna chyli, the abdominal part of the thoracic duct, lumbar trunks, and lumbar lymph nodes, pelvic lymph nodes, and certain organ systems.”⁸

So, amongst all the other benefits of Tai Chi, we can know that correct practice helps our lymphatic system.

1, 2 Introduction to the Lymphatic System: https://training.seer.cancer.gov/anatomy/lymphatic/
3 Interstitial fluid: https://www.biologyonline.com/dictionary/interstitial-fluid
4 Components of the Lymphatic System: https://training.seer.cancer.gov/anatomy/lymphatic/components/
5 "The Lymphatic System: Integral Roles in Immunity", Annu Rev Immunol. 2016 Nov 14;35:31–52. doi: 10.1146/annurev-immunol-041015-055354, Page 1
6 Blausen.com staff (2014). Medical gallery of Blausen Medical 2014
7 Components of the Lymphatic System: https://training.seer.cancer.gov/anatomy/lymphatic/components/
8 Cancer Exercise Training Institute https://www.thecancerspecialist.com/2020/05/01/the-role-of-the-thoracic-duct-in-lymphedema/
† If you have questions about Chinese terms used, you may find About Chinese Terms helpful.