A concussion is a type of brain injury that happens when your head gets hit hard or shaken violently. Think of your brain like a soft, delicate organ floating in fluid inside your hard skull. When you take a serious blow to the head, your brain can bounce or twist inside your skull, temporarily disrupting how it works.

Concussions often happen in contact sports like football, hockey, or soccer, but they can also occur from falls, car accidents, or any hard impact to the head. Someone with a concussion might feel dizzy, confused, or have a headache. They might feel sick to their stomach, see things blurry, or have trouble remembering what just happened. Some people lose consciousness, though many don't.

The tricky thing about concussions is that you can't see them on the outside. There's no cut or bruise that always shows that someone's brain has been injured. That's why coaches, parents, and doctors take them so seriously. If someone might have a concussion, they should stop playing immediately and tell an adult. The brain needs time to heal, and getting another concussion before the first one heals can cause serious, lasting damage.

Most people recover completely from a concussion with proper rest, but it can take days or even weeks.