my son just started walking a few weeks ago, and now that he's mobile it seems like he's constantly hitting his head on something. he's either falling backwards and hitting his head on the ground or wall, or he's hitting his head on something else. i'm really worried that it could cause some sort of brain damage. could it?

i don't think it would cause problems unless he fell from a height afterall all children must go through that stage.

No, if he actually does hurt himself he will have the sign of head injury:

Lathergic
Throwing up
Not wanting to play
falling down (repeatly, like he's dizzy) when walking
when falling asleep not wanting to wake up
and of course, bleeding

My dh accidently smacked my ds head on the chandler (he's 6 months) the other day. Got a huge goose egg but was fine. We called the pedi bc dh was extremely worried (felt terrible of course lol) and he told us to look out for those signs listed above.

Btw, my niece is sitting up on her own and is always layin back and smacking her head on the hardwood floor, she's fine and actually working on crawling. I don't know how many times that girl has smacked her head but everytime she does, she laughs about it!

Speaking of smacking their heads!!!! :eek: My 2 year old smacked his head on a sharp corner of our coffee table while running full tilt! You should see the size of the goose egg on his poor little head. I tried to put an ice pack on it to bring the swelling down but he said that was "owie".
I don't think everyday bumps and bangs can cause brain damage. A good knock to the head that causes loss of conciousness or bleeding though would be something to be concerned about. Don't worry too much about the little bangs.... there will be a lot of them to come, trust me! ;)