Julie
At our medicals they just listened to the childrens chests and checked their eyes, ears. Although, fortunately not an ongoing issue our youngest was critically ill just after he was born and needed lots of scans and tests to check for permanent health problems which luckily there are none, unless being a cheeky monkey counts. We just had to get a copy of all his medical notes/scans from the doctors. they sent them off and didn't charge for them and lucky us, we gained our
PR visa last June.
I think as Kate said, they are more likely to be interested in long term health problems with high treatment costs.
best wishes
Michelle