8 days ago i hit my head, for about 4hrs after i had blurred vision and felt sick, i have had regular pain relief since but still have head pains.

Post traumatic: Headache is considered a form of secondary headache that occurs after head injury. Often accompanying the headache are symptoms of post-traumatic syndrome such as vertigo, blurred vision, memory impairment, reduced attention span, difficulty in concentrating, sleep disturbance, anxiety, depression, mood changes and irritability. Rec.: see your pcp for further evaluation and imaging.