Why brain fog is not normal

Glymphatic drainage, cognitive health & why brain fog should not be normalised

Brain fog is one of the most common — and most dismissed — complaints I hear, particularly from women over 40.

Poor concentration. Word-finding issues. Memory lapses. Mental fatigue that doesn’t improve with rest.

Too often, these symptoms are brushed off with a casual:

“It’s just perimenopause.”

Yes, hormonal shifts matter. But normalising cognitive dysfunction is not the same as explaining it.

Chronic brain fog is a signal that something in the system is not flowing, clearing or recovering properly — and one of the most overlooked contributors is the glymphatic system.

What is the glymphatic system?

The glymphatic system is the brain’s waste-clearance pathway.

It moves cerebrospinal fluid (CSF) through brain tissue to remove metabolic waste produced during normal brain activity, including:

• Amyloid-beta

• Tau proteins

• Inflammatory by-products

• Cellular debris

This process is most active during deep, high-quality sleep.

In simple terms: sleep is when your brain takes out the trash.

If glymphatic flow is impaired, waste accumulates — and cognitive clarity suffers.

Why glymphatic drainage matters for cognitive health

When the brain’s clearance system is compromised, people often experience:

• Brain fog

• Poor focus and concentration

• Memory lapses

• Slower processing speed

• Increased anxiety or low mood

• Waking unrefreshed despite adequate sleep

Over time, impaired clearance contributes to neuroinflammation, accelerated cognitive ageing and increased neurological risk.

This is not about productivity or pushing harder. This is about protecting the brain long-term.

Why brain fog in women over 40 should not be dismissed

Perimenopause can influence:

• Sleep architecture

• Nervous system regulation

• Vascular tone

• Inflammatory load

All of these affect glymphatic function.

But explanation is not permission to ignore the problem.

Telling women that cognitive symptoms are “just part of this stage of life” — without addressing sleep quality, stress physiology, posture, breathing or lymphatic flow — is medical minimisation disguised as reassurance.

Women deserve investigation, not invalidation.

What I look at when improving cognitive function

Brain health is never one-dimensional. When someone presents with brain fog, I assess the entire system that supports overnight brain clearance.

1. Sleep quality (not just duration)

Deep sleep is non-negotiable for glymphatic clearance. This includes:

• Circadian alignment

• Night-time awakenings

• Blood sugar stability overnight

• Alcohol and caffeine impact

2. Nervous system regulation

Chronic fight-or-flight states restrict lymphatic and glymphatic flow. I assess:

• Stress load

• Breathing patterns

• Vagal tone

• Recovery capacity

3. Inflammation & metabolic health

Neuroinflammation interferes with brain clearance. Key considerations include:

• Insulin resistance

• Gut health

• Micronutrient status

• Systemic inflammatory drivers

4. Posture, movement & lymphatic flow

The lymphatic system has no pump — it relies on movement, pressure changes and breathing.

This includes:

• Daily low-intensity movement

• Neck and thoracic mobility

• Sedentary load

• Breathing mechanics

Neck position & soft tissue tension

Forward head posture, jaw clenching and chronic neck tension can mechanically restrict venous and lymphatic outflow from the brain.

If drainage pathways are compressed, clearance efficiency drops.

The collarbone region (thoracic inlet)

Glymphatic outflow connects into deep cervical lymphatic vessels that drain into the thoracic duct and right lymphatic duct near the clavicles.

If the thoracic inlet is restricted by poor posture, shoulder bracing or fascial tightness, lymphatic congestion occurs.

Trying to clear brain waste through a restricted inlet is like emptying a sink with a blocked drain.

The thoracic cavity & breathing mechanics

Restricted rib cage movement and shallow breathing reduce the pressure gradients that drive lymphatic flow.

A stiff, stress-held thorax slows clearance and increases congestion.

5. Fascial tension around the cranium & TMJ

The cranium is not static — it is a fascially connected, dynamic structure.

Cranial fascial restriction can affect:

• Cerebrospinal fluid movement

• Venous and lymphatic outflow

• Pressure dynamics essential for glymphatic flow

Jaw tension and TMJ dysfunction add another layer.

Hypertonicity in the jaw muscles can:

• Increase compression around neurovascular structures

• Reinforce forward head posture

• Maintain a constant sympathetic stress signal

TMJ issues are not just about pain or clicking — they are drainage and nervous system issues.

Restoring flow so the brain can clean itself

When we address:

• Cranial and jaw fascial tension

• Neck mobility and soft tissue restriction

• Thoracic inlet openness

• Rib cage movement and diaphragmatic breathing

• Nervous system downregulation

We are not chasing symptoms.

We are restoring flow.

And when flow is restored, the body can do what it is designed to do:

Allow the brain to efficiently clear waste at night while you sleep.

Brain fog should never be dismissed as something you simply have to tolerate.

It is information.

And when we listen to it — rather than normalising it — we can protect clarity, cognition and long-term brain health well into midlife and beyond.