GlucoSpike AI
Dexcom G6 and G7 Arrow Meanings: What Each One Is Actually Telling You
The full Dexcom trend arrow chart, what each arrow means for rate of change, and why the same arrow can mean different things depending on what you ate.
Seeing a double arrow down on your Dexcom can be a genuinely alarming moment, especially the first few times. Here's what each arrow means, how fast your glucose is actually moving, and what most people do about it.
The full arrow chart
| Arrow | What it means | Rate of change |
|---|---|---|
| Double up | Rising fast | More than 90 mg/dL in 30 minutes (3+ mg/dL/min) |
| Single up | Rising | 30-60 mg/dL in 30 minutes (1-2 mg/dL/min) |
| Up-right (slowly rising) | Rising slowly | 15-30 mg/dL in 30 minutes |
| Sideways | Steady | Less than 30 mg/dL change expected |
| Down-right (slowly falling) | Falling slowly | 15-30 mg/dL in 30 minutes |
| Single down | Falling | 30-60 mg/dL in 30 minutes (1-2 mg/dL/min) |
| Double down | Falling fast | More than 90 mg/dL in 30 minutes (2-3 mg/dL/min) |
These numbers are Dexcom's own published ranges, and they're the same rough logic whether you're on a G6 or a G7. The G7 updates slightly faster, so you may notice its arrows shift a beat sooner than the G6's did.
What the arrow actually tells you to do
The arrow isn't just a mood indicator, it's meant to inform a decision, not just a reading. Dexcom's own guidance (and most clinicians) frame it like this:
- Double down or single down before a meal or activity: worth pausing before insulin or exercise decisions, since your number may keep dropping.
- Steady arrow: the number on screen is a fairly reliable snapshot of where you are.
- Single up or double up after eating: expected for a lot of meals, what matters is how high it climbs and how fast it comes back down.
The arrow is a prediction, not a fact. It's telling you where your glucose is trending in the next 30 minutes, not guaranteeing it.
Why the same arrow can mean different things for you
Two people can both see a single-down arrow after lunch and have completely different explanations: one just took a walk, one is still digesting a high-carb meal, one is a few hours past a large dose of insulin. The arrow tells you direction and speed. It doesn't tell you why.
That's the part a CGM alone can't answer, and it's the piece we built GlucoSpike around. Instead of just watching the arrow after the fact, scanning your meal beforehand gives you a sense of which foods tend to produce those steep up-arrows in the first place, so the pattern starts to make sense instead of just repeating.
Sources: Dexcom trend arrow guidance, Time in Range Coalition, published CGM trend-arrow research.
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