Congenital adrenal hyperplasia refers to a collection of genetic conditions that limit the adrenal glands’ ability to produce essential hormones, especially cortisol. These conditions can occur in both males and females, causing problems with growth and development (including development of the genitals). When diagnosed in infancy or early childhood, patients with the classic and most severe form of congenital adrenal hyperplasia may present with ambiguous genitalia (girls), an enlarged penis (boys), weight loss or difficulty gaining weight, dehydration and vomiting. Later symptoms may include a very early onset of puberty, severe acne, irregular menstrual cycles and rapid growth that culminates in shorter-than-normal height. A typical treatment protocol may include hormone replacement therapy and, when necessary, surgical correction of ambiguous genitalia.