If you’ve ever looked at your child’s pump settings and thought “I know these matter…but what do they actually do?”, you’re not alone.

This guide will help you:

Understand what each setting controls
Know why it matters in real life
Feel more confident spotting what might need adjusting

Because once you understand the why, managing the day to day becomes much clearer.

Is your Pump in Manual or Automated Mode?

Before anything else, this is the most important distinction to understand.

Many children now use automated systems like Omnipod 5 or Tandem t:slim X2 with Control-IQ with a CGM such as a Dexcom G7.

But pumps can run in two ways:

Manual Mode

Basal insulin follows fixed programmed rates
You give all boluses and corrections
The pump does not adjust insulin automatically

You are fully in control.

Automated (Hybrid Closed Loop) Mode

The pump adjusts insulin based on glucose readings
Basal delivery increases/decreases automatically
It works towards a target glucose

The system supports you, but doesn’t replace you.

Why This Difference Matters

In manual mode, your settings must do all the work.

In automated mode, your settings guide the system, but it can step in and adjust.

Summary:

Manual = precise setup is critical

Automated = still important, but more forgiving

Basal Rates (Background Insulin)

Basal insulin is the steady insulin delivered throughout the day and night. To match real life, pumps use timing blocks, different basal rates at different times.

Example:

Early morning rise (hormones) → higher basal
Overnight → lower basal

Why This Matters

Basal keeps glucose stable when your child isn’t eating.

If it’s off, you may see:

Gradual rises overnight
Unexplained dips between meals

Summary: Basal = background stability

In Automated Systems

Basal isn’t fixed

The pump:

Increases insulin during rises
Reduces insulin during drops

Your programmed basal becomes a starting point, not a strict rule.

Summary: Automated basal = flexible, not fixed

Carb Ratio (Insulin to Carb Ratio)

This tells the pump how much insulin is needed for food.

Example: 1:10 = 1 unit covers 10g carbs

Why This Matters

If the ratio is off:

Too weak → post meal spikes
Too strong → hypos after eating

Real world example:

Your child eats 50g carbs:

At 1:10 → 5 units
But if they actually need 1:8 → they'll likely spike

Summary: Carb ratio = controls post meal glucose

Insulin Sensitivity (Correction Factor)

This shows how much 1 unit of insulin lowers glucose.

Example: 1 unit reduces glucose by 3 mmol/L

Why This Matters

Used for correcting highs safely.

If incorrect:

Too aggressive → hypos
Not strong enough → highs linger

Summary: Sensitivity = safe corrections

Target Glucose

This is the levels your insulin pump is aiming for.

Why This Matters

It guides:

When corrections happen
How automated systems respond
How aggressive insulin delivery is

Summary: Target = your system’s goal

Insulin Duration and Insulin on Board

Insulin Duration = how long insulin works in the body (usually 3-5 hours).

The pump uses this to calculate:

Insulin on Board (IOB) = insulin still active

Why This Matters

This setting directly affects safety.

Too short → insulin stacking → hypos
Too long → delayed corrections → highs

Real world example:

You correct a high…then correct again too soon because the pump thinks insulin has finished working → unexpected hypo later.

Summary: Duration = prevents stacking and mistiming

Activity/ Exercise Mode

This setting adjusts the system for movement.

It usually:

Raises glucose target
Reduces insulin delivery

Why This Matters

During activity, insulin often works more strongly. This helps reduce hypos, but doesn’t work perfectly for everyone.

Real life reality:

Some children stay stable
Others spike (especially high adrenaline sports like rugby)
Some families prefer manual adjustments

Summary: Activity mode = reduces hypo risk (sometimes)

Bringing It All Together

These settings don’t work alone, they work as a system:

Basal → background stability
Carb ratio → meals
Sensitivity → corrections
Target → overall goal
Duration → safety
Activity mode → flexibility

And whether you’re in manual or automated mode determines how much the pump adjusts vs how much you do.

Setting Adjustments

These settings are not set once and left forever.

They will change due to:

Growth
Hormones (especially puberty)
Illness
Activity levels
Stress
Even seasons and temperatures

What works today may not work next month, and that’s completely normal.

Adjustments are not a sign something is wrong. They are a part of managing Type 1 Diabetes well.

Final Thoughts

You don’t need to master every setting overnight.

But understanding:

What each one does
Why it matters
And how they interact

turns your pump from something confusing into something empowering.

Understanding Insulin Pump Settings: What Do They Actually Mean?