What Causes Intense Headache,blurry Vision And Concussions On Running?

The last couple of times my daughter has gone out running she gets an intense headache on the right side of her head and everything gets blurry and she can not see. Her pupils get very small and her eyes are all glossy. Then she gets extremely cold. She has had several concussions so now she gets them very easily. He last mild concussion was 6 months ago. Do you think the headache is from the concussions or is something else going on?