What Causes Headaches, Swollen Temples And Stomach Aches?

My daughter just turned 15 and she has been getting bad headaches/ swollen temples/ stomach aches more than usual. At least 4 times a month and especially when she has her period. We have also been noticing when she swims(Year round swimmer) 5 days a week. When she excerts a lot of energy her entire body and face get red? Anything related? d