My son bumped his head last night, only a minor cut on the back, but still bled a lot. he seems to be fine. im still worried about internal injuries. i want to know should i take him to hospital?

Depends on details: Many details are important. After a head bonk, one usually goes to the ER or sees his own doctor if he: vomits more than once, loses consciousness more than 30 seconds, has a headache getting worse over time, has changes in behavior such as getting irritable, has changes in coordination such as clumsiness, is confused such as difficulty recognizing people or places, has changes in speech, etc...