How do painkillers know where on earth to relieve the twinge such as advil, aleeve, etc.?

pain is a referal answer of fretful sistem to a malfunction of body,such as inflamation,congestion of lactic sour in muscules,direct stimulation of spasm receptors in the limb,& etc
in reality painkilling is not a true intelligent machine.the way of distress relife is vary from one drug to another.some of them make smaller the inflamation in the body,so they releave the iflamatory niggle.some another like narcotics effect on intermediate nervous system and decline the sensation of pain.truly these various drugs effect on the systems which are responsible of torment.these drugs have a published effect on integral body & and this is the reason of drug side effects.presently it is an important aspiration for pharmacologists to find more specific drugs for a certain dull pain.
oh,i'm sorry because english is my second language & you should excuse me if you can't take to mean exactly what i mean.
All medication are infused with detailed map of human biology. Some medications work better than others because they are infused next to better maps which is why they might cost more. Sometimes the battery get low and they find lost which is why they don't seem to work somtimes.
Painkillers in reality don't know where to relieve headache. They enter the blood stream and travel all over the body, affecting anywhere you may enjoy pain. For instance, if you win a headache and have a sore leg, taking one pain reliever will affect both pains.
Chris, i am sorry to tell ya but ur wrong, it lately dont work that way.