The Largest Organ You’ve Never Heard Of

What is the largest organ in your body?

Intestines? Nope.

Heart? Definitely not.

Skin? Not anymore.

Recently a new largest organ was discovered. Yes, you did read that right, we’ve discovered a new organ. (Well not us specifically, but we as humans have)

It’s called the Interstitium and it exists all around your entire body.

Now, we know this may be a shock to some of you, so we’re going to fill you in with any information you may need. 

Allows us to break down what the interstitium is.

What is the interstitium?

The interstitium is a network of fluid-filled spaces surrounded by connective tissue: a matrix of collagen bundles. 

It fills in any gap or space in between our organs.

It is structured in a honeycomb-esque format and has been described as a “railway for cells,” or “the internet for the human body.”

It’s been suggested that the “railway”  can affect protein transport and the movement of cancer cells.

Also, it’s been estimated that it holds 20% of all the water in our bodies, a very surprising figure, but when given the circumstances, makes a lot of sense.

What does it do?

The interstitium has a wide variety of properties.

Acting as a protective cushion for our organs, the interstitium has an incredibly important job. It protects all of our organs from internal trauma and external shocks, helping to preserve them and maintain our organs working in perfect condition.

It essentially acts as a shock absorber for your internals, protecting them from the harsh reality of the outside world.

Another function it holds, is the ability to produce lymph fluid. This is transported to lymph nodes to aid your immune cells in fighting diseases. So it’s an essential part of the lymphatic system.

For those who don’t know, lymph fluid is the fuel of immune cells, and is vitally important to keeping your immune system functioning properly.

This leads to suggest that the interstitium is an integral part of our bodies composition, not only providing physical security for our organs, but also chemical security through supplying lymph fluid to our immune system.

Clearly it holds an essential function in the lymph system that in turn, is critical to keeping you as healthy as possible.

When was it discovered, and who discovered it?

The official study surrounding the interstitium was released March 27th 2018. The document contained findings regrading the composition, function, and structure of the interstitium.

The founders were Dr David Carr-Locke and Dr Petros Benios; Two Israeli doctors who came across the organ while investigating a patient’s bile duct, searching for indicators of cancer.

Upon discovering the unusual structure of the interstitium, surrounding the bile duct, they both immediately contacted pathologist Neil Theise for his verdict, who then proceeded to work with them to establish what it was they had found.

All 3 worked collaboratively to produce the report and publish the rather shocking findings.

Why has it only just been discovered?

It seems crazy that an organ this big has remained undetected for so long, but the reasons are valid.

First of all, we did know it was there, we just weren’t sure of it’s composition. See, we thought it was a solid structure, not one filled with fluid – if this had been true we would’ve simply acknowledged it as living tissue.

We now know that the composition is not solid, but fluid filled compartments. The reason we didn’t know this before is because whenever we examined it the tissue samples were cut out and placed on a slide to be examined. 

This led to the fluid draining out, thus making it look like it was just living tissue, and not fluid filled.

So what changed?

Well, we edited a tool called the “endoscope.” 

Previously this tools was used to let us peek inside a human body and has existed in medical practice since the Ancient Greek and Roman periods.

It has since been edited to allow us to view cells on a microscopic level, while still in the body. 

Through using the technique known as “probe-based confocal laser endomicroscopy” the unusual structure of the tissue is what first caught the attention.

As Neil Theise said “I was trained that tissue tears a little bit when you’re making a slide. We thought this was artifact. It turns out that the dense connective tissue appearance was the artifact. These tiny cracks are actually what’s left of the spaces after the fluid has drained out when you fix the issue.”

In short?

Previously we believed that tissue “cracked” when it was removed for a slide (inspection). The reality is, once you break the tissue, the fluid drains out, leaving gaps. 

What can we learn from it?

It may just sound like a system of interstitial fluid and tissue, but there’s a lot more to it than that.

The fact this could be “the internet of the human body” is a BIG statement.

The interstitium could explain the spread of cancer cells, along with certain other cellular diseases. These would be huge developments in medical practice, potentially setting the course for alternate medicine for years.

We assumed cancer cells were transported through blood or just spread one to the next, but the interstitium could explain this instead. 

While some cases will still pass from one cell to the next, and through our blood, what the interstitium can do is give us answers for the anomalies. 

Now that’s useful.

Alongside this, there’s also potential for the interstitium to helps us answer questions such as:

  • Why does skin wrinkle?
  • Why do limbs become stiff?
  • How do inflammatory diseases spread?

See, it’t not just a blob of water existing inside us, there’s a lot more to offer!

How do we use the Interstitium in our practice?

We discovered a surprising connection between the interstitial space and pain and mobility issues. 

The tissue layer can become dense after years of pressure, forcing it together. This restricts mobility as your muscles now have less give, and are much more rigid.

Using ultrasound we can spot these inconsistencies and target them by injecting interstitial fluid consisting of essential proteins into them. This forces the pressurised tissue open, leaving you with more mobility and flexibility.

In short, it’s crucial to our practice and is an area we will be consistently researching. There may be all sorts of properties that we haven’t uncovered yet, so there’s plenty more researching to be done.


We hope you learned something today.

It may be strange hearing there’s another whole organ you’d never heard of, but it’ll certainly feel weird knowing it’s the biggest organ in your body.

Hopefully you now have a better understanding on the scientific discovery and how it affects you, your body, and our practice.

Thanks for reading!

If you’re struggling with mobility or flexibility issues then be sure to schedule a call with us. We’d love to check out your interstitium and make sure you’re fit and healthy!

Ageing doesn’t have to happen, retain your youth with our treatment and remove the pain and discomfort you so desperately hate.