I have heartburn and an upset stomach. it happens frequently. is that acid reflex?

Probably: Acid reflux or gastroesophageal reflux disease (gerd) is a condition in which stomach contents leak backwards from the stomach into the esophagus. This can irritate the esophagus, causing heartburn and other symptoms including nausea, vomiting, difficult or painful swallowing, hoarseness, chronic cough and sore throat. Occasionally, pain from heart disease can feel like "heartburn", so be careful.

Probably: Heartburn is acid reflux, stomach pain can be an ulcer, gastritis or a tumor. You need to be seen and evaluated by a gastroenterologist, probalbe upper endoscopy. You should be on Prilosec or similar drug regularly to prevent development of esophageal cancer due to the frequent reflux.