I surely did not mean to scare you at all, I'm sorry.
Yes a hiatal hernia is when parts of your stomach enter the chest cavity, these are two of the tests I had done....
Barium X-ray. During this diagnostic test, you'll drink a chalky liquid containing barium that coats your upper digestive tract. This provides a clear silhouette of your esophagus, stomach and the upper part of your small intestine (duodenum) on an X-ray. A barium X-ray may help reveal whether the contents of your stomach are backing up into your esophagus.
Endoscopy. In this test your doctor passes a thin, flexible tube equipped with a fiber-optic light and video camera system (endoscope) down your throat and into your esophagus and stomach to check for inflammation. This not only can help detect a hiatal hernia, but also is the most sensitive way to check for damage to your esophagus from acid reflux.
The manometry test is very uncomfortable, they had me lying down, then they inserted the thin tube through my nose and down my throat, but as they raise and lower this tube several times you are sipping water through a straw....the uncomfortable part is getting the tube past your gag reflex.
This test took about 30-45 minutes.
Agian, I'm sorry for making you nervous, but this is 1 test I don't want to repeat.
If you have any other questions, I'll be happy to answer them.
Raising teenagers is like nailing Jello to a tree.