Hi,my son is 12 years old,weighs about 27kg and height about 1.2,1.3. and he was diagnosed with thyroid which is borderline today,what are the symptoms because at times he become very weak that he dont feel like doing anything,he also has a constipation problem which makes him dizzy and sometimes faints when he needs to go to the toiletmwhat could all this be related to.Worried mum