DIABETES TECH TOOLS
How CGMs and insulin pumps actually work — and how to wear one.
Technology can make living with diabetes easier and safer. Tools like continuous glucose monitors (CGMs) and insulin pumps help you keep your blood sugar levels steady and avoid serious highs and lows.
📌 A note on this chapter
The information here is general — devices and pumps differ a lot between brands, and they keep evolving. For specifics on how often to change your sensor or set, what your particular tool can do, and how to use its features, always check with your medical team and your device’s official brand information.
Continuous Glucose Monitoring (CGM)
What a CGM does and where it sits.
📡 What CGMs do
- Track your blood sugar levels and help keep them within target ranges.
- Reduce the risk of dangerously low (hypoglycemia) or high (hyperglycemia) blood sugar.
- Help calculate how much insulin you need.
- Reduce the need for regular finger pricks.
📍 Where it sits
- Usually placed on your skin — upper arm or abdomen.
- Don’t remove it unless it needs to be changed.
- Needs to be changed about every 1–2 weeks.
- Changing parts is quick and easy — you’ll learn from your medical team, and you can also find step-by-step videos online.
Two main types of CGM
For a deeper comparison, see Chapter 18: Finger Prick & CGM.
🔄 Real-time CGM
- Measures blood sugar every 1 to 5 minutes.
- Sends readings automatically to your phone or receiver — no scanning needed.
- More sophisticated alarms for highs and lows.
- Components: a sensor with a transmitter, plus a smartphone or receiver that displays the data. Newer devices often combine the sensor and transmitter into one all-in-one unit, instead of a separate clipped-on transmitter.
📲 Intermittently scanned CGM
- Measures blood sugar every few minutes too.
- Traditionally needs scanning of the sensor to see and save results.
- Components: a sensor-and-transmitter combo (usually on the upper arm) and a reader — either a dedicated handheld device or a smartphone.
- The line is blurring — some of the newest devices and apps can stream readings continuously too, but most still rely on scanning, and alarm features tend to be more limited than on real-time CGMs.
Insulin Pumps
Small devices that deliver insulin throughout the day.
💉 The basics
- Usually used together with CGMs.
- Small devices that deliver short-acting insulin continuously over 24 hours.
Placing your pump
A few rules of thumb that make wearing it easier.
📏 Where it goes
- Pinch an inch: place it where you can pinch a small pad of skin.
- Keep distance: don’t place it within 2 inches of a CGM.
- Avoid problem areas: thickened skin, swelling, or lumps.
How insulin pumps work
How they work — and how they make daily life easier.
⚙️ How it works
- Use only short-acting insulin.
- Deliver small doses throughout 24 hours (basal insulin).
✨ How it helps
- Can help calculate insulin needs based on carb intake.
- Recommend doses you can confirm or adjust.
- Deliver correction doses if your blood sugar is too high or too low.
- Send reminders so you don’t forget your mealtime insulin.
- For more on the medications themselves, see Chapter 12: Insulin & Medication.
Things to remember
A few practical points worth keeping in mind.
⚠️ Good to know
- You can remove pumps if needed.
- Once removed, you’ll be without insulin while it’s off — see Chapter 14: Sick Day Management for situations where this matters more.
- Some pumps are not waterproof.
Pump types
Insulin pumps come in 2 main types, and each works a little differently in how it delivers insulin.
🔌 Tethered (tubed) pump
- Includes a pump, a tube, and an infusion set.
- A soft tube/cannula under the skin delivers the insulin.
- Pump can be clipped to clothing, kept in a pocket, strapped to your leg, or placed between bra cups.
- Change cannula/infusion set usually every 2–3 days.
- Pump itself can last for years.
- Need to change the insulin reservoir regularly.
- Some pumps are waterproof, others aren’t.
🩹 Patch pump
- Pump attaches directly to the skin.
- Includes both reservoir and cannula in one unit.
- Controlled with a handheld device or phone.
- Worn on areas like upper arm, abdomen, hip, buttock, or thigh.
- Units are usually changed about every 3 days.
- Often waterproof (you can swim and bathe with them).