Hormones are chemicals secreted into the blood from glands, such as the pituitary and adrenal glands. They work as part of a complex network, referred to as the endocrine system. The endocrine and nervous systems work together to form the control systems of the body. A balanced hormonal system is able to correctly govern growth, sleep cycle, mood, immune system, metabolism, hunger, sexual arousal and fertility, among other things. Hormones prepare your body for both immediate and long-term changes. From sending a flight-or-fight signal during an emergency, to initiating the physical changes of puberty or menopause, hormones are the messengers of our chemical communication system. Understanding hormones helps us to identify symptoms of an imbalanced system, and take appropriate actions to address the problem. Grab the book to discover more