Intense feelings of love use the same parts of the brain that pain uses. So preliminary research shows that when you're feeling madly in love, you are less likely to feel physical pain.
Love takes up where pain leaves off, brain study shows
Maybe this is why a break up hurts so much? Because you're now feeling pain you haven't felt in a while?
The study also shows that distraction alleviates pain, too. This is something you can use. Next time you feel pain, enumerate sports that don't use balls -- or think of your favorite food, or your happy place.