Endocrinology is the study of hormones. Hormones are essential for our everyday survival. They control our temperature, sleep, mood, stress, growth, and more.
An endocrinologist is a doctor that treats diseases related to problems with hormones. A hormone is a chemical messenger that travels from one cell to another. Hormones are released in one part of the body, travel in the bloodstream, and have an effect on another part of the body. This helps different parts of the human body to communicate with each other. Hormones are secreted by endocrine glands, such as the pituitary, thyroid, or adrenal glands. Not all glands are classified as endocrine glands; for example, sweat glands or lymph glands are not endocrine glands.
Hormones are found in all organisms with more than one cell, and so they are found in plants and animals. They influence or control a wide range of physiological activities, such as growth, development, puberty, level of alertness, sugar regulation and appetite, bone growth, etc.
There are whole sub-specialties devoted to specific areas where hormones work. For example:
- Pediatric endocrinology, looking at hormones in children
- Thyroid endocrinology, looking at how the thyroid affects metabolism
- Endocrine-disrupting chemicals, where chemicals which mimic the effects of hormones are present in the environment
- Comparative endocrinology, which looks at the way similar hormones work in different species (e.g. from insects, through to fish, birds, mammals, etc)