An endocrinologist is a doctor who specializes in the diagnosis and treatment of diseases caused by hormonal imbalances. The endocrine system is a network of glands and organs that produce different hormones. Hormones affect every organ system in the body including the heart, kidneys, brain, skin, and lungs. When there is too much of a hormone or not enough, a part of the body can become diseased. The result could be thyroid cancer, osteoporosis, infertility, obesity, or slow growth in children. Due to the wide array of patients and conditions, endocrinologistsoften choose to specialize in a particular type of patient, organ, or disease. Learn about this exciting career today!