What is the reason for the pain of pressing the upper left three fingers of the navel?

This pain belongs to the stomach, may be caused by stomach lesions, such as gastritis, gastric ulcer, gastric reflux disease, etc. Also rule out the possibility of cholecystitis, because the pain of the gallbladder will also radiate to this part, you should promptly seek medical advice to do stomach and gallbladder examination, if necessary, may need to do gastroscopy.