My Son Is 20 Years Old. 2 Months Ago He

My son is 20 years old. 2 months ago he was in a car accident. He flipped his truck on its side. he was not hurt not even a scratch. but now his head hurt like someone his hitting his head on both sides. and he says that his right side hurts right under the rib cage. him too. could his symptoms be cause of his accident or is it something else.