In countries where practices are permitted before adulthood, the number of children and adolescents undergoing treatment aimed at delaying or with a view to transition is increasing. Although reliable data is limited, the quest for gender identity appears to be more widespread with greater social acceptance of gender dysphoria manifesting in individuals who feel their biological sex does not match their gender identity. But hormonal treatments are not without effect on the growing body of children and adolescents. For example, transgender youth who receive hormone therapy aimed at delaying puberty or gender reassignment have lower bone mineral density (BMD) than expected for their age, regardless of gender assigned at birth.