Brief Answer: Your pre-existing gastric conditions is the cause Detailed Answer: Hello sir and welcome. Thank you for writing to us. I have gone through your query with diligence and would like you to know that the symptom of nausea in your case has many conditions that could clearly be causing it right in your medical history. Acid reflux, history of gastritis, hiatus hernia, and the esophagus condition. I would like to say that this symptom should not be appearing this often if all these conditions are being well managed and treated. If at all you are on any medications for these conditions, please do write back to me so I can help you with a proper regimen further sir. If you are not on medications to address all these conditions, it is best you visit your doctor and first get adequately examined and then accordingly treated for them so you do not experience any further symptoms or discomfort. I hope you find my response helpful sir. Please feel free to write back to me for any further clarifications, I would more than happy to help you. Best wishes.