If you run too much what happens
Good and Bad.

Well in a bad way if you run to hard too much you can strain your leg or get runners knee.
In a good way you build up inner-self, confidence, stronger leg muscles and help you maintain a good live with organs and heart.
Running HELPS alot.
Hope it helps :)

The good: u will get in great shape, feel awesome, can dance all night, (among other things) & feel fantastic.

The bad: If u run on pavement, u can mess up ur knees. Then the doctor can say' ''Well, u can stop running for a few months or years, or u can have surgery.''

l stopped. My knee was still swollen 2 years after quitting.

The really bad: (but it has nothing to do with running): the fun really started about 12 years later, when l slipped on a marble floor & shattered my kneecap into 6 pieces. That was 10 years ago. l do not run anymore, & sometimes need a cane when my knee pops out of place. l miss running. l loved it even as a kid. Oh well. Keep it up.
But try, if possible to run on a track, sand or trail.