Post-concussion syndrome is when someone gets hit in the head really hard and starts feeling sick and dizzy afterwards. This can happen in sports or accidents. The head is like a computer, and when it gets hit, it can cause some wires to get all mixed up. This can make a person feel really tired, achy, and like they can't think straight.
The person might have trouble remembering things, and they might feel really grumpy or emotional. They might also have headaches or trouble sleeping. This is because the brain got hurt and needs time to heal.
The good news is that most people feel better after a little while. Doctors might tell the person to rest, avoid screens like phones or TVs, and take medicine for pain. They might also give the person special exercises to do to help their brain heal faster. It's important to listen to the doctors and take it easy until the brain feels better.