Continuous Glucose Monitors & Insulin Pumps
What the alarms mean, why continuous glucose monitor readings lag behind a finger prick, and what to do when the tech misbehaves.
Rhiannan's pump and CGM demonstration
A hands-on tour of a real pump and continuous glucose monitor, video coming soon.
What to know
Reading the arrows
A CGM shows a glucose value plus a trend arrow. A down arrow means falling and a double down arrow means falling fast, the direction matters as much as the number.
Continuous glucose monitor lag
A CGM measures fluid under the skin, so it trails blood glucose by roughly 5 to 15 minutes. When glucose is moving quickly, or the reading doesn't match how the person feels, confirm with a finger prick.
Urgent low alarms
An urgent low or predicted low alert deserves action, not dismissal. Treat as a hypo and confirm with a finger prick where possible.
Pump troubleshooting
A pump delivers rapid-acting insulin only, so an interruption raises glucose within hours. Check the site for pain, redness or leaking, check the tubing for kinks or bubbles, and read the on-screen alarm. Unexplained highs plus a pump often mean a failed site.
Never remove someone's device
Don't disconnect a pump or remove a continuous glucose monitor unless the person asks or a paramedic directs it. Tell attending paramedics that they wear a pump or CGM.
What to do, in order
- Read the number and the arrow together.
- Confirm with a finger prick when readings and symptoms disagree.
- Treat an urgent low alert as a hypo until proven otherwise.
- For an unexplained high on a pump: check site, tubing and alarms, and prompt them to follow their backup plan.
- Tell emergency services about any pump or continuous glucose monitor they are wearing.
Test your instincts
Read each situation, then reveal the options.
A colleague's phone alarms in a meeting: 3.6 mmol/L with a single down arrow. They say they feel fine.
What's the best action?
Show the optionsHide the options
Your child's continuous glucose monitor reads 4.5 and steady, but they're shaky, pale and say they feel low.
Who do you believe?
Show the optionsHide the options
Someone you support has been sitting at 18 mmol/L for a few hours despite corrections. They wear a pump.
What's worth checking?
Show the optionsHide the options
This is general first aid education, not personal medical advice. In an emergency in Australia, call 000.