Hello. Thanks for asking form HCM. I can understand your concern. It is good that the mode of injury was mild as hitting plastic cup usually not cause dangerous head injury. You also mentioned that he went to sleep and there was difficulty in waking him up. It could be due to tiredness or head injury. You can check it by waking him up completely. If after waking up, he responds normally and remains conscious, oriented, it is good. If he does not wake up at all consult ER as soon as possible. Also you should observe him for few other signs which suggest dangerous signs : vomiting : bleed through nose/ear/throat : fits : loss of consciousness or decreasing consciousness : onset of new focal deficit : persistent headache not responding to painkillers : Pupillary dilatation which is not responding to light If any of above signs, consult ER as soon as possible. The doctor might advise CT head to rule out fracture or brain bleed. Fracture is usually managed conservatively while bleed may require surgery. If no above signs, do not worry about pain and purple colored lump. These are manifestations of head injury. For pain and swelling, you can follow few tips : Apply icepacks at injury site : You can give him painkiller like Diclofenac sodium after prescription : Avoid pressure at injury site : Keep his head at higher level than chest : Swelling and purple colour will subside on its own in 10-14 days. : Still no relief, you can consult doctor. Hope it will help him. Thanks. Take care. Dr Ishu Bishnoi