Doctors can you tell me when should i know to be concerned about a head injury?

Several: Unconscious laceration bone exposed skull fracture penetrating injury persistent headaches seizures are all warnings!of severity.

Impaired function: Head injuries can cause headaches, nausea, arm or leg weakness immediately. Later, the effects of a concussion can be present, that would affect your physical state, thinking ability, emotional state, and can affect your sleeping pattern. If you are concerned, see a physician who can evaluate you for post-head injury symptoms.