<s>[INST] hi well im a teenager and last night i hit my head really hard on my dads trunk door. it didnt hurt as much as i thought it would and i slept fine but im pretty sure my head has a bump on it and it hurts. i also have a throbbing feeling. and im dizzy and VERY worried. should i go to the ER? [/INST] HIT hank for asking to ChatDoctorI really appreciate your concern you said here that you had accident that hurt your head, in case of any head injury the 48 to 72 hours of observation is necessary because anything could happen during this period if nothing is happened during this period then no need to worry about this, if nothing have happened immediately the also nothing to worry, hope this information helps you, have nice day. </s>