What tests will my child have to find the cause of fainting attacks?

Fainting. First a good history and physical by your child's physician.This will allow for appropriate testing as indicated. This may include an ekg, blood work, or referral to a specialist. Fainting is fairly common and may not require an extensive workup. Fainting during exercise, or resulting in injury, is a red flag.
See below. There may not be any testing needed. A lot of what maybe required depends on the history/details of the fainting spells. If there is concern, then your child may get an ekg, a cardiac echo, or tilt table testing.