💧 Still or Sparkling Water — Does Your Lymphatic System Actually Care?

 

“Drink more water — it flushes your lymphatics.”

“Sparkling water isn’t as hydrating as still water.”

“If you’ve got swelling, you need to drink more water.”

They are the sort of statements that get repeated so often that they begin to sound like facts.

And you know me.

When something involving the human body is presented as a nice simple rule, I usually end up disappearing down a research rabbit hole.

First things first — your lymphatic system doesn’t need “flushing”

Let’s get that one out of the way.

Our lymphatic system (read more on the lymphatic system here) plays an essential role in fluid balance, immunity and the transport of substances from our tissues back towards the circulation.

But lymph isn’t dirty water sitting in pipes waiting for us to flush it through.

Our smallest initial lymphatic vessels begin within the tissues. These lead eventually into collecting lymphatic vessels, which have valves and smooth muscle and are capable of their own rhythmic contractions.

Movement, muscle activity, tissue forces, respiration and changes in pressure also form part of this beautifully dynamic system.

So when somebody tells you that drinking another litre of water will “flush your lymph”, the physiology is considerably more complicated than that.

And considerably more interesting.

💧 Does hydration matter then?

Absolutely.

Water is fundamental to human physiology.

Our cardiovascular system, kidneys, hormones, electrolytes and tissues are continually interacting to maintain fluid balance.

And the lymphatic system is part of that picture.

What I wouldn’t say is:

More water = more lymph flow.

We don’t have evidence for such a simple relationship.

Normal hydration supports normal physiology.

That’s rather different from prescribing huge quantities of water as a lymphatic treatment.

And this is where I want to go underneath the skin for a moment.

Because lymphatic vessels don’t exist in isolation.

💦 Water, fascia and the space between

You knew I’d manage to get fascia into this somewhere.

But actually, it really does belong here.

When we look at an anatomy picture of the lymphatic system, we usually see beautiful green vessels laid over a body.

Useful — but also slightly misleading.

Because those vessels don’t float independently inside us.

They live within tissue.

The extracellular matrix surrounding our cells contains collagen, elastin, proteoglycans, glycosaminoglycans, ions and a considerable amount of water.

And one particularly interesting component is hyaluronan — HA.

HA is an abundant glycosaminoglycan within connective-tissue extracellular matrix and has a strong relationship with water. Reviews of fascial biology describe the extracellular matrix as a hydrated environment in which HA and other GAGs contribute to fluid retention and mechanical behaviour.

In other words, healthy living tissue isn’t the dry white stuff we see in anatomy books.

It’s wet.

💧 Hydrophilic — quite literally “water loving”

This is a word worth knowing.

Hydrophilic means having an affinity for water.

Hyaluronan and other components of the extracellular matrix have hydrophilic properties. Water associated with this matrix contributes to its physical and mechanical behaviour.

And HA is particularly interesting in fascia.

Researchers have identified HA-rich loose connective tissue at interfaces between fascial layers, and HA concentration varies according to anatomical location and the sliding requirements of different fasciae.

So when I think about fascia, I don’t think of dry sheets of clingfilm wrapping muscles.

I think: Fibres. Cells. Fluid. Ground substance. Sliding interfaces. Movement.

And then, sitting right within that environment… lymphatic vessels.

🌿 The lymphatic vessels within the tissue

This is where fascia and lymphatics become particularly interesting to me.

Initial lymphatic capillaries are blind-ended vessels lying within the interstitial tissues.

Their endothelial cells are connected to the surrounding extracellular matrix by tiny structures called anchoring filaments.

Changes in the surrounding tissue and interstitial pressure can therefore mechanically interact with the lymphatic capillary. Those relationships help facilitate the entry of interstitial fluid into initial lymphatics.

So rather than imagining:

tissue + separate lymphatic pipe

I prefer:

a living relationship between fluid, tissue, movement and lymphatic vessel.

And that is why hydration interests me.

But here’s where we need to be careful…

 

It’s incredibly tempting to take all of that lovely physiology and conclude:

“If you’re dehydrated, your fascia dries out, stops gliding and your lymph stops flowing.”

And I’m not going to tell you that.

There is good evidence that fascia contains HA, water and a hydrated extracellular matrix; that HA is associated with fascial sliding; and that lymphatic capillaries mechanically interact with the extracellular matrix around them.

What we don’t have is evidence for the neat chain:

drink water → hydrate fascia → improve glide → increase lymph flow.

Human physiology rarely gives us such convenient arrows.

And although dry skin can sometimes occur alongside dehydration, looking at someone’s dry skin doesn’t allow us to see the hydration state of their deeper fascia or lymphatic tissues.

So this isn’t another hydration hack.

It’s a reason to appreciate that normal hydration is part of the environment in which our tissues normally function.

That distinction matters.

🫧 So what about sparkling water?

 

Now we come back to the bubbles.

Plain sparkling water is water containing dissolved carbon dioxide.

And it still hydrates you.

A randomised trial involving 72 healthy, euhydrated men compared 13 commonly consumed beverages. After participants drank one litre, researchers measured fluid retention and urine production.

At four hours, cumulative urine output after sparkling water wasn’t significantly different from still water.

That study doesn’t answer every possible question about hydration in every population.

But it gives us no reason to say:

“Sparkling water doesn’t count.”

It does.

🫧 But isn’t sparkling water acidic?

 

Yes — slightly.

Dissolved carbon dioxide forms carbonic acid.

But that does not mean sparkling water acidifies your blood.

Your lungs and kidneys are part of highly regulated systems maintaining acid-base balance.

So the acidity of the water in your glass shouldn’t be confused with the pH of your bloodstream.

🫁 Where the bubbles might matter — your tummy

Now we’ve reached something much more practical.

How do you feel after drinking it?

Some people can drink sparkling water all day without giving it a second thought.

Others end up feeling like they’ve swallowed a balloon.

Carbonation can cause gastric distension and sensations of bloating or fullness.

And if your abdomen feels particularly full or uncomfortable, taking a lovely expansive diaphragmatic breath might simply feel less comfortable.

That doesn’t mean:

“Sparkling water blocks lymphatic drainage.”

It means:

you’re bloated.

And that’s an important distinction.

🫁 Breathing and lymphatics

 

This bit interests me enormously too. (Read more on breathing here)

Breathing changes pressure within the chest and abdomen and has long been considered one of the external mechanical influences upon lymph movement.

A 2026 systematic review looking specifically at thoracic-duct pressure and flow found respiratory activity influenced flow and/or pressure in five of six human studies and twelve of seventeen animal studies.

But — and this is important — the researchers also concluded that the overall evidence remains inconsistent because the studies used different methods and produced variable results.

I love research like this.

Not because it gives us another definitive answer.

Because it reminds us not to pretend we know more than we do.

Breathing appears relevant.

Exactly how respiration, intrinsic lymphatic contractions, circulation and other mechanical forces interact in the living human is still being explored.

That’s science.

🧂 And don’t blame everything on the bubbles

 

There’s another practical consideration.

Sparkling water, sparkling mineral water, soda water and tonic water aren’t necessarily the same thing.

Depending on the product, you may have minerals, added sodium, sugar or sweeteners.

So instead of:

❌ Fizzy = bad
✔ Still = good

I’d suggest doing something much less exciting.

Turn the bottle around and read the label.

Sometimes the boring bit on the back tells us far more than the wellness claim on the front.

💦 “But I’m swollen — shouldn’t I drink loads of water?”

 

Not necessarily.

And this is where I think we need to stop treating swelling as though it were one condition.

Swelling can have many different causes.

Lymphatic dysfunction is one.

Venous problems are another.

Medication, injury, surgery and systemic medical conditions can all contribute too.

So neither:

“Drink loads and flush it out.”

nor

“You’re retaining water, so stop drinking.”

is sensible blanket advice.

I’d much rather ask:

Why are you swollen?

Because that’s the question that determines what needs to happen next.

🟢🟠🔴 Fi’s Hydration, Lymph & Swelling Traffic Light

 

🟢 GREEN — KEEP IT SIMPLE

You’re generally well and drinking normally.

Still water suits you? Great.

Prefer plain sparkling water? That’s fine too.

You’re drinking regularly, you’re not excessively thirsty and you’re not experiencing new or unexplained swelling.

Normal hydration + normal movement + comfortable breathing.

No lymphatic detox required.

🟠 AMBER — NOTICE THE PATTERN

 

Perhaps:

sparkling water makes you noticeably bloated;

you’re deliberately forcing down litres of water because you’ve been told it will “flush your lymph”;

you’re restricting water because you’re frightened of making swelling worse;

or swelling is becoming persistent or behaving differently.

This is where I’d stop following blanket advice and look at the individual.

What are you drinking?

How much?

What’s changed?

What medication are you taking?

Is there a history of surgery or cancer treatment?

Is the swelling localised or generalised?

Context matters.

If sparkling water means you drink more and you enjoy it, those bubbles don’t somehow cancel out the water.

If it makes you uncomfortably bloated, still water may suit you better.

But I’m much less interested in whether your water has bubbles than I am in the bigger picture:

Are you normally hydrated?
Are you moving?
Are you breathing comfortably?
How are your tissues behaving?
And, if you’re swollen — do we know why?

Because your body isn’t a collection of separate systems.

Fascia, interstitial fluid, lymphatics, circulation, muscles, respiration and movement all meet one another.

And that’s the bit I find fascinating.

💚 A little note from me

 

My work with lymphatics isn’t about “detoxing” people or promising to flush fluid away.

It’s about understanding why something may be happening and working with the whole person.

If you’ve noticed swelling that is persistent or changing, my 🟢🟠🔴 Swelling Traffic Light is a useful place to start.

And where appropriate, lymphatic assessment and treatment, movement, breathing and wider rehabilitation may all become pieces of that person’s puzzle.

Sometimes we need treatment. Sometimes we need movement. Sometimes we need medical investigation.

And sometimes…

we really can just enjoy the fizzy water.

When swelling doesn’t quite make sense…

If you’ve noticed swelling, heaviness, tissue changes or a feeling that something just isn’t quite right, it can be difficult to know where to start.

My approach is to look at the whole picture — your history, movement, breathing, tissues, scars where relevant, and what the swelling itself is telling us.

Sometimes the next step may be lymphatic treatment. Sometimes movement or self-management strategies may help. And sometimes the most important thing I can do is recognise that something needs further medical assessment.

The aim isn’t simply to move fluid. It’s to understand why it’s there.

I offer lymphatic and lymphoedema assessment and treatment from my clinic in Clacton-on-Sea, with monthly appointments also available in Bury St Edmunds.

Want to know whether an appointment might be appropriate for you?
Visit pilatestherapyandbodywork.com to find out more or BOOK AN INITIAL LYMPHATIC TREATMENT

🐇📚 Fi’s Reading Rabbit Hole

For those of you who, like me, love a bit of a deep dive…

You absolutely don’t need to read research papers to enjoy a glass of water.

But if I’ve made you curious about what is happening underneath your skin, here are some of the papers that sent me down this particular rabbit hole.

💧 Does sparkling water actually hydrate?

Maughan RJ et al. (2016) — A randomized trial to assess the potential of different beverages to affect hydration status.

This is the Beverage Hydration Index study: 72 healthy euhydrated men, 13 beverages, four hours of urine measurements. Sparkling water did not produce significantly different four-hour cumulative urine output from still water.

Maughan et al. on PubMed

🕸️ Now we’re into my territory — fascia & hyaluronan

Stecco C et al. (2011) — Hyaluronan within fascia in the etiology of myofascial pain.

Human fascial samples examining the distribution of HA within loose connective tissue layers. This is one of the papers that makes the relationship between fascia + HA + sliding interfaces so interesting.

Stecco et al. on PubMed

💦 How much HA is actually in different fascia?

Fede C et al. (2018) — Quantification of hyaluronan in human fasciae.

I particularly like this one. The researchers measured HA in fascia from different anatomical sites and found differences related to the sliding properties of those tissues.

Fede et al. on PubMed

🐇 Deeper still — HA and the fascial environment

Hyaluronan and the Fascial Frontier (2021).

A useful open-access review looking at HA within the extracellular matrix, its relationship with water and its possible relevance to fascial mechanics and gliding.

Read the full open-access review

🌿 Where fascia meets lymphatics

Interaction between the extracellular matrix and lymphatics.

This is where the rabbit hole gets particularly interesting: extracellular matrix, HA, lymphatic endothelial cells and the interaction between lymphatics and the tissues in which they sit.

Read the open-access review

🫁 And finally… breathe

The physiology of thoracic duct pressure and flow (2026).

A systematic review looking at respiration, circulation and intrinsic lymphatic contractility. I particularly like this paper because the answer isn’t conveniently black and white: respiratory influences appear in much of the literature, but the authors emphasise the variability and limitations of the evidence.

Read the 2026 open-access review

And that is probably enough rabbit hole for one glass of water. 🐇💧