Definition
A hormone produced by the pancreas that regulates blood glucose (sugar) levels by allowing the body's cells to absorb and use glucose for energy. People with diabetes mellitus may not produce enough insulin, or their bodies may not respond to it properly, and some require injected insulin to control their blood sugar.
Plain English
A natural body chemical that controls blood sugar. Some people with diabetes have to inject it because their body doesn't make enough on its own.
Context Anchor
Seen in aviation medical certificate discussions, especially when a pilot reports diabetes or the use of insulin medication.
Derivation
From the Latin insula, meaning 'island.' The hormone is named after the islets of Langerhans -- small island-like clusters of cells in the pancreas that produce it. Knowing this helps a pilot understand why insulin issues are tied to pancreatic function in medical discussions.
Why Pilots Care
Pilots using insulin for diabetes must obtain a special issuance medical certificate, as the condition and its treatment are evaluated for flight safety.
Intuition Check
Insulin is not the disease itself. It is the body chemical, or the medicine, used to control blood sugar; the aviation concern is whether the pilot’s blood sugar can stay stable enough for safe flight.
Example Sentence 1
A pilot who uses insulin to manage diabetes must apply for a Special Issuance medical certificate and meet specific monitoring requirements.
Example Sentence 2
FAA guidelines require additional testing for any applicant who takes insulin.