Congenital hyperinsulinism (HI) is a disorder that causes low blood sugar (hypoglycemia) in infants and children. Congenital hyperinsulinism is rare; most children's hospitals encounter only one or two cases a year. Since October 1998 the Congenital Hyperinsulinism Center at The Children's Hospital of Philadelphia has evaluated and treated more than 400 patients — making it the largest program of its kind in North America. Providing full services for congenital hyperinsulinism requires sophisticated, multidisciplinary team capabilities. Our Center includes a team of specialists in endocrinology, pediatric surgery, pathology and interventional radiology who have significant experience treating infants with this condition.