Hormones are substances produced by your body itself in the endocrine glands. The function of hormones is to control various processes in the body. They either drive or inhibit organs and tissues. There are hormones that directly affect body processes such as your blood pressure and emotions. An example is adrenaline, the hormone that enables us to take immediate action. Your body also has hormones that play a role in body processes that run for longer periods of time, such as your growth and development.