 Despite the designation " possible " , someone with a visceral AVM and a family history but no nosebleeds or telangiectasias is still extremely likely to have HHT , because these AVMs are very uncommon in the general population . At the same time , the same cannot be said of nosebleeds and sparse telangiectasias , both of which occur in people without HHT , in the absence of AVMs . Someone 's diagnostic status may change in the course of life , as young children may not yet exhibit all the symptoms ; at age 16 , thirteen percent are still indeterminate , while at age 60 the vast majority ( 99 % ) have a definite diagnostic classification . The children of established HHT patients may therefore be labeled as " possible HHT " , as 50 % may turn out to have HHT in the course of their life . 
