When I was a child, I experienced something painful. Literally painful. I was having chest pains, with difficulty breathing. I felt tingling in my fingers, sometimes I would feel sweaty or chilly. It happened at odd times, with no real cause, and I never knew when it was going to happen.
Of course, I told my parents. Honestly, they didn't believe me. Even when it eventually happened in front of them, they thought I was faking. But, it kept happening, and I remember my mom at one point telling me they were going to waste money to take me to the doctor so he could tell me it wasn't happening.
A few weeks later, I was seen by a doctor. He ran a few tests and told my parents that he thought I was just under physical stress, caused by eating too much, and not getting enough sleep. Mind you, I got more sleep than most of my peers, thanks to my extremely early bedtime, and I was skinny and always hungry.
Thankfully, the chest pain and difficulty breathing slowly got farther between episodes. Now, with the benefit of hindsight, I am aware that what I was experiencing were the symptoms of panic attacks. they were really scary.