Hormones play an integral part in the balance and workings of the body. While many people are broadly aware of their existence, there are many misconceptions and few are aware of the nature and importance of the endocrine system. In this Very Short Introduction, Martin Luck explains what hormones are, what they do, where they come from, and how they work. He explains how the endocrine system operates, highlighting the importance of hormones in the regulation of water and salt in the body, how they affect reproduction and our appetites, and how they help us adjust to different environments, such as travel across time zones. In this fresh and modern treatment, Luck also touches on the ethical and moral issues surrounding research methods, testing on animals, and hormone misuse. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.