KEEPING TRACK OF THEIR CHILD’S BLOOD counts becomes a way of life for parents of children with brain or spinal cord tumors. Unfortunately, misunderstandings about the implications of certain changes in blood values can cause unnecessary worry and fear. To help prevent these concerns, and to better enable parents to spot trends in the blood values of their child, this appendix explains the blood counts of healthy children, the blood counts of children being treated for brain or spinal cord tumors, and what each blood count value means.