What Is the Lymphatic System?

This is probably the most important fundamental question for understanding Manual Lymphatic Drainage and, honestly, in my opinion, understanding our bodies and our health.

And yet, so few people, even within the medical and wellness world, can actually answer it.

I’m Nicole Shea, and I’m a lymphatic educator committed to bringing up-to-date, science-based information about the lymphatic system to bodyworkers, medical professionals, and anyone else who will listen to me!

So… what actually is the lymphatic system?

I like to say that the lymphatic system is a body system made up of vessels, lymph nodes, organs, and specialized lymphatic tissue. It is so much more than the “toilet” of the body.

Yes, the lymphatic system helps remove excess fluid and cellular waste. But that is only part of the story.

The lymphatic system is deeply involved in fluid balance, immune function, inflammation, dietary fat transport, and the movement of cellular and tissue byproducts.

And this is where I want you to start thinking about the lymphatic and immune systems as sisters or, in some ways, as one interconnected system.

The lymphatic system provides the house, the highways, the dispatch system, and important sites for the production and maturation of immune cells. Lymph nodes are meeting places where immune cells encounter and respond to foreign material. Lymphatic vessels transport immune cells and antigens through the body and help coordinate immune surveillance. Then, once the fluid is "cleaned", it transports that fluid back to the bloodstream.

And then there’s one of my favorite mic-drop moments:

The lymphatic system transports dietary fat.

Yes. Fat.

Remember those little lacteals you learned about in high school anatomy class? Those are specialized lymphatic capillaries inside the villi of your small intestine. They pick up dietary lipids that are too large to enter the blood capillaries directly and transport them through the lymphatic system before they eventually enter the bloodstream.

So the lymphatic system isn't just cleaning up after the party.

It is actively participating in what your body absorbs, transports, and does with the nutrients you eat.

And yes, we absolutely need to talk about waste removal.

Lymphatic capillaries weave through the interstitial space (the watery environment surrounding your cells). This is where fluid, proteins, immune cells, and other substances move between the blood and tissues.

When cellular debris (dead bits of cells after the breakdown of metabolism) needs to leave the interstitial space, the lymphatic system is one of the major routes out.

If the environment surrounding your cells isn't being properly cleared of debris, cellular interactions are slowed and impaired, and tissue function can be affected.

This is one reason I don't like reducing the lymphatic system to simply being the body's “garbage disposal.” It is much more sophisticated than that.

The lymphatic system is constantly helping maintain the environment in which our cells live, while also participating in immune surveillance and transporting important substances throughout the body.

Healthy lymphatic function is fundamental to healthy tissue function.

I sometimes call it the body's innate healing system because it is working for you every minute of every day.

And we're still learning more.

One of the most fascinating areas of lymphatic research is the brain. We now know that the brain has its own specialized systems for clearing fluid and waste, closely connected with the lymphatic system and the meningeal lymphatics, called the glymphatic system. Which brings us to a whole other question:

How does your brain drain?

Check out this article for info on the brain drain.

I've developed an educational course for LMTs on advanced manual lymphatic drainage, and another on the connections between the lymphatic system and the brain, specifically for the potential use of MLD for Alzheimer's Disease. You can find those on my course page.