The hormonal system (called the endocrine system in medical terminology) influences your metabolism, growth and many other functions. In the hormonal system, glands secrete chemicals known as hormones into the bloodstream or surrounding tissue.
What is the hormonal system?
You have a number of glands that secrete hormones, including the hypothalamus, the pituitary gland, the pineal gland, the thyroid gland, the parathyroid glands, the adrenal glands, and the pancreas, ovaries and testes.
Each gland makes one or more hormones. Each hormone has specific cells in the body it can influence. Some hormones, such as growth factor, influence almost all the cells in the body. Other hormones influence a small number of cells, such as the anti-diuretic hormone (ADH), which only influences particular cells in the kidney.
How does the hormonal system work?
When a hormone is released from a gland, it travels through the body. It passes by most cells, but eventually reaches its target.
When it reaches its target, it attaches to a particular type of cell, known as a receptor cell. The receptor cell then does something that it is ordered to do by the hormone. That something might be to grow faster, or to release another hormone, or to absorb sugar from the blood, or to withhold water from the kidneys, or one of many other important functions in the body.
In effect, the hormone system is the way in which one part of the body (the gland) tells another part of the body (the target cell) to do something important.
Find out more about the main endocrine glands and their hormones.
Medical conditions related to the hormonal system
The hormonal system can go wrong. Glands might produce too many or too few hormones, or the target cells might stop responding properly to the hormones.
The more common hormonal problems are:
- thyroid problems like hypothyroidism or hyperthyroidism
- Cushing's syndrome
- some fertility problems
- congenital adrenal hyperplasia.
These are usually treated by controlling how much hormone your body makes. An endocrinologist (endocrine gland specialist) can help with appropriate testing and treatment.
Last reviewed: July 2017