Endocrinology is the study of hormones and glands, covering topics like the adrenal, pituitary glands, and diseases related to hormone imbalances like diabetes and thyroid disorders. Most universities do not offer dedicated endocrinology programs, instead offering modules or fellowships, and the structure of training varies by country. Careers in endocrinology include research, private practice, and working with other specialists; there is increasing demand for endocrinologists given diseases like diabetes affect hundreds of millions worldwide.