I hav a hiatal hernia & never hav heartburn, but I always hav mild to severe upper central chest/ back pain that come & go often. Can it be my hernia?

"HIATAL HERNIA" PAIN. Be sure you rule out cardiac etiology first. Do not assume your chest pain is from the hernia.
Hiatal hernia. Yes. Hiatal hernias (slipping of the upper portion of the stomach where the esophagus comes in to a position above the diaphragm) can cause either fairly severe acid symptoms, treatable with Zantac (ranitidine) or prilosec, or pressure from the mass effect of the organ in the wrong position or from intermittent obstruciton of food. You don't always have both types of symptoms.