DD (15 months) has occasional temper tantrums in which she holds her breath until she passes out. I used to do this as a child too.
She also does this if she gets a fright.
I discussed it with a health worker last time I saw one (few months back) and am aiming to make a Doc appointment for a check up on this but I have been advised it's fairly common. Particularly so if there is a family history.
However, one thing that was flagged up was potentially low iron levels compounding the issue.
DD is a vegetarian (as am I) and although I do my best to provide a healthy diet she is currently going through a 'picky' phase. Any ideas of iron rich foods that I can shovel in first before she throws a wobbly (and the food) and refuses to eat anything other than custard?!