Can a sliding hiatal hernia ever get well by itself?

Not really. These types of hernias won't fix themselves, but really are not dangerous or need treatment. They are fixed during operations performed for reflux disease, But otherwise just left alone. They can get larger over the years, but there's no specific activities or diet to avoid to prevent this. Hope this helps!
Nope. Depending on your symptoms you may want to talk to a surgeon about getting it fixed.
Not really. A hiatal hernia is an anatomic abnormality that cannot correct itself. However, people mistakingly refer to a "hiatal hernia" when they mean gastroesophageal reflux disease (gerd). Many people with gerd have no hernia and many people with hiatal hernias do not have gerd. Gerd can respond very well to conservative measures such as changes in diet, wt loss, medication, etc.