My mother has this slight chest pain below her breastbone. She has been having this for two years from now and we did a full body checkup two years ago. The doctor said it must be a gastric issue or gastritis. Her oxygen levels are 96 to 99. Her pulse rate is 90 to 100. She doesn't get this often. This pain comes and goes (observed after 2 to 3 days) Is there anything to look out for? She doesn't have any other difficulty in breathing. Please do let me know if there is anything I should do beforehand.