The Importance of the Lymphatic System to Inflammation

You just dropped an iron on your big toe.

After crumpling to your knees and spewing a curse word or two, you know what’s going to happen. Your toe will turn bright red, it’ll get very hot to the touch, it will be sore and puffy. You may not be able to move it for a while. These are all signs of inflammation, your body’s natural defenses coming to the rescue.

What you can’t see is the dilation of the blood vessels, which allow more blood to reach the tissue. This blood contains a gang of white blood cells rushing into the wounded tissue, ready to fight a battle against infection. Inflammatory mediators trigger immune system cells to pass out of the small blood vessels to prevent further tissue damage. Hormonal signals irritate nerves and cause pain. Inflammation, from the Latin “inflammare”( to burn), sounds an alarm to your entire body. If something hurts, you’re more likely to notice and protect that body part. 

Inflammation also involves interstitial fluid, which pools into the affected area.

Your body contains about 12 liters of interstitial fluid, a clear fluid composed of sugars and proteins. This fluid bathes and cushions every cell in the body. It helps organs hold their shape and eases functionality. Think of it as cushiony, liquid packing material. When injured or under stress, blood capillaries also leak this watery fluid, adding to the effect of swelling, or edema, to the affected tissues.

An injury or a reaction to a surgical procedure is a common occasion for inflammation. A virus, like the flu or pneumonia, also presents a similar course of physical signs. Acute inflammation is a crucial way for the body to fight disease and injuries.

Now, chronic inflammation is a little different. This can be your body’s reaction to stress, toxins (like cigarette smoke and artificial fragrances), excess adipose tissue, cancer, or a compromised immune system. Unlike acute inflammation, chronic inflammation doesn’t always have that initial, alarming effect. It can build up around organs, or settle into more distal tissues, causing long-term damage. Chronic inflammation quietly wreaks havoc on your immune system.

Most people have a general idea of what happens when their body is inflamed, but what happens when it heals? Where does that excess fluid go? When you’re recovering from a bout of inflammation relating to an organ, or a mild case of swelling; what is actually happening?

Enter the Lymphatic System...

The lymphatic system is your body’s unsung immunity hero. The lymphatic system also plays a vital role in removing the swelling and other effects that come with inflammation. 

Eventually, interstitial fluid needs to move. Here’s how that works.

Running approximately along the same path as the circulatory system, the lymphatic system comprises lymph vessels and lymph capillaries, as well as lymph nodes which are clustered in specific areas of the body. The lymphatic system works with the circulatory system, but it functions very differently.

interstitial fluid is taken in through lymph capillaries and vessels, which move it toward lymph nodes and finally toward the neck and thoracic cavity where the two main ducts are located. Once inside the lymph vessels it is no longer called interstitial fluid. it is called lymphatic fluid, or simply “lymph.”

Also –– and this is important –– lymph doesn't circulate as blood does. It only moves in one direction.

Blood has a powerful pump, the heart, which sends blood to the lungs for oxygen, and then back to the heart where it is then pumped to the rest of the body. It has a long way to go to get through your entire system, but it relies on powerful heart contractions to make the journey.

The lymphatic system has nothing of the sort. The role of the lymphatic system is to take up interstitial fluid that is just “hanging around” the body and move it toward lymph nodes. The only way this can happen is through pressure exerted on the flaps.

In a healthy body, the natural pressure of the fluid building up against the lymph vessel wall is all that’s needed. Each lymph vessel is made up of a chain of lymphangions, short segments (<2 cm) of flapped links. Think of a chain with flaps along each link that takes in liquid, then seal shut. Once the seals are closed, fluid is propelled through to the next link in the chain. When enough interstitial fluid fills in the spaces between tissues and presses up against the lymph vessels, those small lymphangions, or lymph collectors, take the fluid in through flaps. The lymph then chugs along inside the vessels toward the lymph nodes.

Here, impurities, toxins, and errant cells, (including cancer cells) are broken down and removed. In a normally functioning body, the lymphatic system is constantly cleansing you with fresh fluid, but when you’re inflamed somewhere, the lymph system must work harder. Your lymph system carries away all that waste and sends it to lymph nodes. There, the nodes attack lymphocytes and other bad cells, breaking down the nasty bits.

The purified fluid then returns to the blood through two main ducts, the right duct and the thoracic duct. About the diameter of coffee stirs, these ducts deliver the freshened fluid back to the blood via the subclavian veins.

So what does this have to do with inflammation? 

Inflammatory swelling is a pooling of interstitial fluid. Normally, this effect combats infection and disease. When the work is done and tissues begin to recover, the lymph vessels capture that fluid. In a healthy body, the lymphatic system moves about 4 liters of lymph every day! For reference, the circulatory system moves about 5 liters of blood daily.

Movement of fluid is essential to good health!

If the lymph system doesn’t function properly, fluid can pool in the tissues and around organs, causing severe cases of swelling, or edema. 

Stagnation of the lymphatic system can prolong inflammation, or worse, trigger chronic inflammation or lymphedema, which often begins in the extremities, like the feet or hands. 

The natural way to get lymph moving

Natural, controllable methods of moving lymph are breathing and exercise. 

If you’re not breathing and moving, lymph pools in the vessels and doesn’t do its job to carry inflammation (and that extra fluid) away from affected tissues. This is why deep breath-work and exercise are so crucial to a healthy immune system and a body’s ability to heal. 

Sometimes the lymph system gets overwhelmed, though. Too much fluid causes an overload to the lymphatic system. Manual lymphatic drainage is a form of massage where the practitioner's hands encourage lymphangion action, improving movement of lymph up to 20% more than normal, unaided lymphatic movement. 

An inflamed body with stagnant lymph benefits from manual lymphatic drainage if the lymphatic system isn’t able to properly function on its own.

I’ve been studying the lymph system so that I have a better understanding of what actually goes on when performing manual lymphatic drainage. I learned the techniques in my MLD training in the fall of 2019. But like any body of knowledge, the more you know, the more questions you have. I keep going back to the books, as well as supplemental scientific materials, to make sure I have a decent grip on the subject.

I hope to be able to explain this in simple language, for my good and that of my clients. My goal is to share the basics of the lymphatic system. If you have any questions about this, please post them in the comments or contact me. I will research the answers and report them. For personal inquiries, please feel free to send me a direct message.