Loss of consciousness, vomiting, change in behavior, unequal pupils, visual changes, unsteady gait, and memory loss are some of the major symptoms that require further attention. It is not uncommon to have minor headaches, but severe headaches should be evaluated. Even if your child is asymptomatic, it is important to watch them closely for the next 12 hours or so for any new symptoms. It is also important that if your child is symptomatic after a head injury that he or she should not return to competitive sports until they have had medical evaluation. As always if you are concerned about your child, it is better to err on the side of seeking medical attention then worrying all night.