<s>[INST] My son fell at an amusement park today about 4 hours ago and hit his head on the concrete curb. He was examined by paramedics and I have been watching him very closely. He seems to be acting normally. However, he has a bump on the back of the head. Is it normal for the bump to hurt? How long will it hurt? Can he take a nap? [/INST] From the scenario what you have said I think it must be a hematoma... Hematoma means collection of blood.if your son didn't have any loss of consciousness or vomiting there nothing much to worry .just give hot water compression for two days. Haematoma usually gets absorbed in 3 to 4 days. He can paracetamol for pain.he can sleep in one side so that u can avoid compression of hematoma which might cause pain for initial two days. I hope I have answered you queries... Get well soon... Have u good day... </s>