I have a 14yo daughter who is very thin 100 lbs but farely healthy. Should I worry Dr ran test for thyroids ? and for anemia . He also said she has irregular heart beat. I am stressing she is not ill I just took her for her physical. My daughter is 5 4, 100 lbs eats everything never sick just normal flu once a year has always been healthy. However she is a Monster and soda addict.