my son is 15 years old he has issue with breathing when playing rugby. I have taken him to specialist respiratory after there examining him with all records from gp etc they also checked for asthma. the specialist said the symptoms appear to be in the vocal cord area larynx im sorry i can t remember the exact words however what he did say was the vocal cords area has muscle and it appears they are closing up because of maybe stress the brain is sending message to that area STRESS . which makes sense because it has only started to happen over the last year he made it into a premier rugby side which has all high profile players the standard is very high. it got to the stage i have had to pull him out of the team because the last game he played after the game he started to hyperventilate i rushed him to hospital they examined him after full examination sent him home saying was a breathing issue hence us going to the respiratory specialist to try to get to the bottom of it.