Dry mouth and yellow urine in the morning may be caused by drinking too little water and concentrated urine, and heartburn may be caused by acid reflux. Dry mouth in the morning is mostly due to the phenomenon caused by drinking too little water, yellow urine may be due to the phenomenon caused by the reduction of circulating blood, urine concentration, most of them are normal phenomena, do not have to worry too much. Heartburn is a phenomenon caused by acid reflux, most people do not have heartburn in the morning, if there is heartburn to suspect reflux esophagitis, gastritis and other diseases, through gastroscopy for differential diagnosis. To summarize, if you feel unwell, please consult a doctor in time.