How grief shows up in the brain, nervous system, and body

Grief doesn’t only live in the heart.
It moves through the brain, the nervous system, and the body.

That’s why grief can change how you sleep, eat, think, remember, and feel - often all at once, and often in ways that don’t make sense.

These changes aren’t signs that something is wrong with you.
They are signs that your body is responding to something overwhelming.

Take what helps.
Leave what doesn’t.

The survival brain (fight, flight, freeze)

What it normally does
Keeps you safe by scanning for danger and reacting quickly.

In grief, it can stay switched on longer than usual.
That can look like:

• anxiety or panic

• anger or irritability

• fear that appears without warning

• feeling constantly on edge or easily startled

What to know
This isn’t overreacting.
It’s a nervous system that learned the world is no longer predictable.

The thinking brain (goes quieter)

What it normally does
Handles reasoning, planning, decision-making, and focus.

In grief, it often takes a back seat.
That can look like:

• brain fog

• trouble concentrating

• forgetting simple things

• struggling to make decisions

What to know
Your brain is prioritising survival over clarity.
That’s not failure — it’s triage.

Nervous system states (freeze, collapse, surge)

What it normally does
Moves between states of activation and rest to help you cope with stress.

In grief, it can get stuck or swing suddenly.
That can look like:

• numbness or disconnection

• exhaustion or shutdown

• bursts of energy followed by crashes

• feeling “not quite here”

What to know
Numbness isn’t absence.
It’s protection.

Body rhythms (sleep, appetite, energy)

What they normally do
Regulate rest, hunger, and physical energy.

In grief, these rhythms often change.
That can look like:

• difficulty falling or staying asleep

• sleeping much more than usual

• loss of appetite or increased eating

• deep, persistent tiredness

What to know
Your body is adjusting to a world that suddenly requires more effort just to exist.

Memory and focus

What they normally do
Help you store information, recall details, and stay oriented in time.

In grief, memory can become unreliable.
That can look like:

• forgetting conversations or appointments

• losing track of days or weeks

• difficulty recalling words or names

What to know
Grief affects the parts of the brain responsible for memory.
This is common, and temporary for many people.

Why this understanding matters

Understanding what’s happening won’t make grief disappear.

But it can soften the fear that something is wrong with you.
It can replace self-blame with context.
And it can make the experience feel less frightening.

These are responses, not failures.
They are confirmations that your body is doing its best with something enormous.

You’re allowed to take only what you need,
and leave the rest.

This space isn’t going anywhere.