Endocrinologist (Hormones)
An endocrinologist specializes in endocrinology, a branch of medicine dealing with disorders of the endocrine system and its specific secretions called hormones. The endocrine system includes the pituitary, thyroid, adrenals, ovaries and testes, and pancreas. These glands secrete hormones or chemical messengers into the blood. Hormones have a variety of effects, but can include stimulation or inhibition of growth, activation or inhibition of the immune system, regulation of metabolism, and preparation for a new activity (e.g., fighting, fleeing) or phase of life (e.g., puberty). Hormones also control the reproductive cycle. Examples of endocrine disorders include diabetes and osteoporosis. Endocrinologists are specialists of internal medicine or pediatricsReference: http://en.wikipedia.org/wiki/Endocrinologist