I was wondering what are signs of having a concussion?

Varied: A concussion may occur without a loss of consciousness. A hit on the head that leads to 'seeing stars or having one's bell rung' is a concussion. Some of the signs and symptoms of concussion include: headache, nausea/vomiting, slowness in thinking, dizziness, sensitivity to light, sensitivity to sounds, either sleeping too much or too little. These usually resolve by 6 weeks.

Concussion: Concussions typically can occur after a head injury. It doesn't have to be a severe head injury or have loss of consciousness. It depends on the severity of the injury. The symptoms can include headache, dizziness, vision change (blurred vision/ double vision), nausea/vomiting. If your symptoms or headache are severe, or if you have a loss of consciousness, you should get evaluated immediately