My 23 Year Old Daughter Is Having Trouble With The

My 23 year old daughter is having trouble with the following. After eating, she gets a migraine, feels lightheaded and dizzy, suffers memory loss and anxiety. It is also sometimes accompanies by chest pain and fatigue. It is worse after eating sugary or high fat foods, but happens to some extent after eating anything. She also feels some of the same symptoms after exercising or taking a bath. She had a CT scan of the abdomen with a gastro and it didn't show anything. She has always noticed that after showering, blood pools in her legs and her legs become very red and hot to the touch. Another issue she has is her nails turning blue. Is this a blood flow issue? Since the gastro didn't have any answers, what sort of doctor would you recommend she see??