How does insulin actually work in the body?

The easiest way to understand insulin is to think of it as a microscopic key.

When you eat food, your body breaks down the carbohydrates into glucose (sugar), which then enters your bloodstream. This glucose is meant to be the primary fuel for your body's cells, giving you the energy to move, think, and breathe. However, glucose cannot just float directly into your muscle or fat cells on its own. The "doors" to your cells are locked.

This is where insulin comes in. Insulin is a hormone produced by the pancreas. When sugar enters your blood, insulin is released and travels to your cells. It inserts itself into a receptor on the outside of the cell—turning the lock. Once the door is open, glucose can leave the bloodstream and enter the cell to be burned for energy.

When you have "insulin resistance" (the driver of Type 2 diabetes), your body is still making keys, but the locks on your cells are jammed. The insulin tries to open the door, but the cell won't respond. Because the glucose can't get inside the cells, it just continues to build up in your bloodstream.