Why I See Boundaries as a Key Health Intervention (A Functional Medicine Perspective)

From my own experience, and from years of working with women whose bodies feel tired, reactive, or permanently on high alert, boundaries aren’t a mindset exercise or a personality trait. From a functional medicine perspective, they’re a key health intervention.

Let me explain. In a nutshell - poor boundaries act as a form of chronic stress. And chronic stress alters how the nervous system, gut, hormones, immune system, and metabolism function. Over time, the body adapts in the only way it can — by becoming more reactive, more inflamed, and less resilient.

This is why boundary strain so often shows up as physical symptoms rather than emotional ones. The body isn’t malfunctioning — it’s responding intelligently to the environment it’s been asked to survive in.

How poor boundaries affect the body

In functional medicine, we always ask two core questions:

1. What load is this system under?

2. How well can it adapt?

Weak or porous boundaries increase load. Not metaphorically but biologically.

When someone regularly overrides their own limits, the nervous system stays in a low-grade threat response. Cortisol rhythms flatten. Blood sugar becomes less stable. Digestion is deprioritised. Immune tolerance drops. Inflammation becomes easier to trigger.

This is why chronic boundary strain is commonly associated with:

• bloating, reflux, constipation, or loose stools

• food reactions or histamine-type symptoms

• anxiety that feels “wired” or chemical

• exhaustion that rest doesn’t fully resolve

• hormonal symptoms that worsen under pressure

• simmering resentment followed by guilt

You can eat well, supplement perfectly, and still struggle if your system never feels allowed to rest.

Leaky boundaries and the leaky gut metaphor

There’s a metaphor I often use with clients because it captures the pattern so clearly.

Leaky boundaries often mirror a leaky gut.

On a physical level, intestinal permeability occurs when the gut barrier becomes inflamed or overstretched — allowing things through that were never meant to cross. The immune system responds, inflammation increases, and symptoms follow.

On a metaphysical level, leaky boundaries work the same way.

Too much comes in. Not enough is filtered. The system becomes reactive. Over time, tolerance drops.

This doesn’t mean boundaries cause gut issues in a simplistic way. But it does highlight how the body and nervous system reflect the same underlying theme: containment matters.

Healthy systems, whether digestive or emotional — need clear edges.

Can boundaries really affect gut health and hormones?

Yes — because boundaries directly influence the nervous system, and the nervous system governs digestion, hormonal signalling, immune balance, and repair.

When the body perceives safety:

• the vagus nerve (the calming branch of the nervous system) activates

• digestive enzymes and stomach acid increase

• gut motility improves

• inflammation downshifts

• hormonal rhythms stabilise

When boundaries are consistently crossed, even subtly, the body stays in protection mode. Healing becomes harder not because the protocol is wrong, but because the environment hasn’t changed.

A familiar clinical pattern

Let me describe a very familiar client pattern; not a real individual, but a composite of many women I’ve worked with.

She came with digestive symptoms, fatigue, and a constant sense of being on edge. She described herself as capable, dependable, and resilient. Others relied on her. She was the one who held things together.

As we explored her history, a pattern emerged. She rarely said no. She absorbed emotional labour at work and at home. Beneath the surface was a steady, quiet resentment, not explosive, just persistent. And that resentment made her feel ashamed. She believed it meant she wasn’t grateful enough or coping well enough.

From a functional medicine lens, the picture was clear. Her nervous system was overloaded. Her digestion was compromised. Her immune system was reactive. Her symptoms weren’t random — they were adaptive.

Why resentment is an important health signal

Resentment is not a character flaw. It’s information.

It often signals:

• chronic over-giving

• suppressed stress responses

• lack of recovery time

• ongoing boundary violations

In physiological terms, resentment reflects allostatic load — the cumulative wear and tear of prolonged stress on the body.

Ignore it, and the body will express the message another way.

The turning point: safety, not confrontation

The shift in these scenarios didn’t come from dramatic boundary-setting conversations or radical life changes. It came from permission.

Permission to pause before responding.

Permission to disappoint others slightly instead of herself completely.

Permission to treat bodily signals as data, not inconvenience.

We worked gently. Small experiments. Leaving earlier. Saying no once a week. Letting someone else carry the emotional weight without rescuing.

As her boundaries strengthened, her symptoms lessened. Digestion improved. Energy stabilised. The resentment drained away. Not because her life became easy, but because her body no longer felt constantly overrun.

That’s not mindset magic. That’s physiology responding to safety.

Reframing boundaries as healthcare

Many women resist boundaries because they’ve been taught that limits equal selfishness. From a health perspective, the opposite is true.

Boundaries:

• reduce nervous system load

• support vagal tone

• improve digestion and immune tolerance

• stabilise hormones

• lower inflammatory burden

They are not walls. They are protection. When your capacity is protected, your body doesn’t have to shout to be heard.

The quiet truth

You can follow every protocol and still struggle if your life continually asks your system to override itself.

Sometimes the most powerful intervention isn’t another supplement or test. It’s allowing the nervous system to stop being on high alert.

From a functional medicine perspective, boundaries are not optional extras.

They are a foundational part of healing.

And for many women, they are the missing piece that allows everything else to finally work.