Type 1, Type 2, Prediabetes: What's Different

Type 1, type 2, and prediabetes are three different stories. Knowing which one you're dealing with changes what you do about it.

Most of us left school with the word "diabetes" and not much under it. Something about sugar. Maybe a grandparent who checked their blood with a finger prick. The word gets stretched across three conditions that behave differently, start differently, and need different things from you.

That blurriness isn't harmless. It's how someone ends up believing type 1 was caused by eating candy, or that a prediabetes result is already a diabetes diagnosis. This is what the word is really holding.

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Insulin is a hormone your body makes to move sugar out of your blood and into your cells, where it gets used for energy (Punthakee et al., 2018). Picture it as the key that unlocks the door. No working key, and sugar builds up in the blood instead of fueling you.

Every version of diabetes lands in the same place: blood sugar that runs too high because insulin isn't doing its job. What separates them is the reason the key stops working (ElSayed et al., 2025). And this isn't a rare problem to have. About 3 in 10 people in Canada are living with diabetes or prediabetes right now (Diabetes Canada, 2024). There's a fourth kind, gestational diabetes, that develops in pregnancy and usually clears afterward; it's close enough to its own subject that it gets its own post (Punthakee et al., 2018).

Type 1: the immune system turns on the body

In type 1 diabetes, the immune system attacks and destroys the cells in the pancreas that make insulin (Quattrin et al., 2023). The body stops ...

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