I think my friend has a problem... she constantly has her child tested for various medical things even though?

the dr. says he is a healthy little boy. she can't accept that for some reason and is constantly taking him back and forth to new and different dr.s to have him pricked and probed and checked out for various thins like allergies, asthma, diabetes, urine infections, mood disorders... but the tests come back fine... do you think she has a probelm what should i do?