I am nursing student specializing in pediatrics and just learned yesterday that head banging outside of temper tantrums can be a sign of hypertension. These poor little kiddos get headaches with hypertension and dont know how to make them stop. Another sign to look for is waking up in the middle of the night screaming because our blood pressure is at its highest in the evening.
If you want ot get it checked out . . . take him to your pediatrician and get his blood pressure measured on THREE DIFFERENT OCCASIONS . . . I know that sounds like a pain but it is done twice to diagnose it in adults and kiddos are even more difficult because doctor offices often make them nervous and that alone can raise their blood pressure. Makre sure they take the blood pressure at the same place each time (ex: left leg, left arm, etc) and I would write them down myself . . .note time of day, where the blood pressure was taken and the result.
I am not sure about behavioral issues or if there have been any major changes in your family but it was fresh in my mind from our cardiology review so I thought I would post . . . feel free to email me if you have any additional concerns.
Good luck J.!
R.