Endocrine Terminology

Endocrine system

A system of glands that releases hormones into the bloodstream.

Hormone

A chemical messenger produced by endocrine cells or glands.

Pituitary gland

A major endocrine gland that regulates many other endocrine glands.

Hypothalamus

A brain region that controls many endocrine functions through the pituitary gland.

Thyroid gland

A gland in the neck that produces hormones regulating metabolism.

Parathyroid glands

Small glands that regulate blood calcium levels mainly through parathyroid hormone.

Adrenal glands

Glands located above the kidneys that produce hormones including cortisol and epinephrine.

Pancreas

An organ that produces digestive enzymes and endocrine hormones including insulin and glucagon.

Pineal gland

A gland that produces melatonin and helps regulate sleep-wake cycles.

Gonads

The ovaries and testes; produce sex hormones and reproductive cells.

Insulin

A hormone that lowers blood glucose by promoting glucose uptake and storage.

Glucagon

A hormone that raises blood glucose, especially by stimulating glycogen breakdown in the liver.

Epinephrine

A hormone involved in the fight-or-flight response; increases heart rate and prepares the body for rapid action.

Cortisol

A steroid hormone involved in stress response, metabolism, and immune regulation.

Aldosterone

A hormone that increases sodium reabsorption and helps regulate blood pressure and fluid balance.

Thyroxine (T4)

A thyroid hormone that helps regulate metabolism.

Triiodothyronine (T3)

A thyroid hormone that strongly influences metabolism.

Calcitonin

A hormone that lowers blood calcium levels by promoting calcium deposition in bone.

Parathyroid hormone (PTH)

A hormone that raises blood calcium levels.

Melatonin

A hormone produced by the pineal gland that helps regulate sleep-wake cycles.

Growth hormone (GH)

A pituitary hormone that promotes growth and influences metabolism.

Prolactin

A pituitary hormone that stimulates milk production.

Oxytocin

A hormone involved in uterine contractions and milk ejection.

Diabetes mellitus

A group of disorders characterized by abnormally high blood glucose.

Type 1 diabetes

An autoimmune disease in which pancreatic beta cells are destroyed, causing little or no insulin production.

Type 2 diabetes

A disorder involving insulin resistance and inadequate insulin production.

Hypoglycemia

Abnormally low blood glucose.

Hyperglycemia

Abnormally high blood glucose.

Diabetic ketoacidosis (DKA)

A dangerous complication involving severe insulin deficiency, high blood glucose, and buildup of ketones.

Hypothyroidism

Underactive thyroid resulting in insufficient thyroid hormone.

Hyperthyroidism

Overactive thyroid resulting in excessive thyroid hormone.

Goiter

Abnormal enlargement of the thyroid gland.

Graves disease

An autoimmune disorder causing hyperthyroidism.

Hashimoto thyroiditis

An autoimmune disorder that commonly causes hypothyroidism.

Cushing syndrome

Disorder caused by prolonged excessive cortisol exposure.

Addison disease

Adrenal insufficiency resulting in inadequate production of adrenal hormones.

Acromegaly

Excess growth hormone in adults causing enlargement of bones and tissues.

Gigantism

Excess growth hormone during childhood causing excessive linear growth.

Diabetes insipidus

A disorder involving inadequate antidiuretic hormone action, causing excessive urination and thirst.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH)

Excessive ADH activity causing water retention and low blood sodium.