Hormones: The Body's Chemical Messengers

Hormones are the body's chemical messengers. They travel through the bloodstream to tissues and organs, and they work slowly, over time, affecting many processes throughout the body, including:

• growth and development;
• metabolism;
• sexual function;
• reproduction;
• mood.

Where hormones come from

Hormones are made by endocrine glands — special groups of cells. The major endocrine glands are:

• the pituitary;
• the pineal;
• the thymus;
• the thyroid;
• the adrenal glands;
• the pancreas.

Men also produce hormones in the testes, and women in the ovaries.

Small amounts, big effects

Hormones are powerful: a tiny amount can cause big changes in cells, or in the whole body. That is why having too much or too little of a particular hormone can be serious.

When hormones go wrong

A hormone disorder can occur when hormone levels are too high or too low, or when the body does not respond to a hormone the way it should. Stress, infection, and changes in the balance of fluid and electrolytes in the blood can also affect hormone levels.

In the United States, the most common endocrine disease is diabetes, and there are many others. They are usually treated by controlling how much of a hormone the body makes; if the problem is too little of a hormone, supplements can help.

Testing hormone levels

Laboratory tests can measure hormone levels in blood, urine or saliva, and a health care provider may order them if you have symptoms of a hormone disorder. Home pregnancy tests work in a similar way: they detect pregnancy hormones in urine.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Hormones." https://medlineplus.gov/hormones.html
• MedlinePlus, "Endocrine Diseases," used for what causes hormone disorders, diabetes as the most common, and how they are treated: https://medlineplus.gov/endocrinediseases.html
• Rewritten in hubnx's own words.