Clearly if you’ve had some sort of impact or trauma to your head, you should always see a doctor. You need to be aware of any concerns, headaches, dizziness, and behavioral changes. You need to seek emergency medical care if there’s any of these types of signs following a recent blow or traumatic injury to the head.
Even a mild injury to the brain is still a serious injury that requires prompt attention and an accurate diagnosis. So it’s certainly recommended that even if you feel that the injury wasn’t that significant, but you’re showing some signs or some symptoms that you need to seek emergency medical care.