Hormones have a crucial part in a child's development and growth. The endocrine system is often at the basis of problems with growth, puberty, and sexual development. Certain hormones produced in a child's brain, for example, control the child's growth, puberty, and metabolic function (how the body breaks down and uses food as energy). Hormones are released into the bloodstream through the endocrine glands. Serious health problems, such as diabetes, can emerge when there is an imbalance or the endocrine glands are not functioning properly. Endocrinology is the study of these glands and hormones. A paediatric endocrinologist is a doctor who specialises in the treatment of children who have problems with hormones or glands. A paediatric endocrinologist sees patients with issues that are significantly different from those encountered by an adult endocrinologist. Hormonal imbalances can last a lifetime. Pediatric endocrinologists are educated to treat these problems in children of all ages, from infancy through adolescence.