My 12 yr old grandson bruises very easily. is it something to be concerned about?

See Dr.: 12 year olds generally are very physically active, so it may be a normal variant at his age, but if there is concern, see a dr., let them know your concerns, ... And a few routine blood tests will assure there is nothing to be concerned about.

Depends: A certain number of bruises is expected in active kids and usually located over bony prominences like shins and elbows. Bruises over a soft belly or body surface not prone to impact would be worrisome. A doc visit would be in order.