An endocrine gland is a small organ in your body that makes special chemicals called hormones and releases them directly into your bloodstream. Think of endocrine glands as tiny factories that produce powerful messenger molecules, sending instructions to different parts of your body about how to grow, when to feel hungry, how much energy to use, and countless other vital functions.

Your body has several endocrine glands working together like an invisible communication network. The pituitary gland in your brain controls growth and tells other glands what to do. The thyroid gland in your neck regulates how fast your body uses energy. Your pancreas makes insulin, which helps your cells use sugar from food. The adrenal glands sitting atop your kidneys produce adrenaline, a hormone that gives you that burst of energy and focus when something exciting or scary happens.

The word endocrine comes from Greek words meaning “secreting within,” which perfectly describes how these glands work: they release their hormones internally, straight into the blood, rather than through tubes or ducts like other glands do. Your salivary glands, for comparison, send saliva through ducts into your mouth, so they're not endocrine glands.

When endocrine glands work properly, you barely notice them. But when something goes wrong, like when someone's pancreas doesn't make enough insulin, they can develop diabetes and need medical help to stay healthy.