Okay, so when people play American football, they sometimes run into each other really hard and their heads bump together. When this happens, it can hurt their brains and make them feel funny.
You know how your brain is like the control center for your whole body? Well, when a person gets a concussion from playing football, it can mess up the way their brain works for a little while.
Some of the things that might happen to a person when they get a concussion include a headache, feeling dizzy or lightheaded, having trouble balancing or walking straight, feeling sleepy, or trouble remembering things that just happened. These symptoms might not show up right away - they might take a few minutes or even hours to show up.
When someone thinks they might have a concussion, it's important that they take a break from playing right away and see a doctor. They will probably need to rest and take it easy for a while, and not play football until they feel better. If someone gets too many concussions, it can be really bad for their brain in the long run. So it's important for players and coaches to be careful and take care of themselves and each other!