When your dentist injects lidocaine into your gums,the drug blocks the pain of the oncoming drill, but it also blocks all other sensation – leaving your mouth feeling numb and swollen. What whether there were a drug that could specifically block pain, and but leave the rest of your sensations alone? In order to do this,you would need to find a way to control the cohort of nerve fibers that transmit the specific type of pain you would like to block.
Source: phys.org