Glucagon is a hormone that raises the level of glucose in the blood. The alpha cells of the pancreas, in areas called the islets of Langerhans, make glucagon when the body needs to put more sugar into the blood. Glucagon binds to a receptor on liver and muscle cells (called the glucagon receptor), stimulating the cells to release glucose.
For people with type 1 diabetes, the pancreas does not release insulin, making them unable to adjust insulin levels in response to glucose levels, and type 1 diabetes can also impede the secretion of glucagon, making them at risk for severe low blood sugars.
If you have type 1 diabetes, you should have an emergency glucagon kit as part of your toolkit. The recent approval of nasal glucagon is a game-changer for treating severe low blood sugars. Glucagon isn't only for rescue use, though - some PWD are mini-dosing glucagon and seeing good results.