I just hit my head kind of hard while skateboarding. and was wondering if in like 3 to 4 hours i would be ok to take a nap.

Perhaps: Hard to,know from scant information. Was this the only head strike recently? If you lost consciousness, were confused or had a seizure, then You require a doctor’s evaluation. If it was only a head strike without other symptoms except pain, and you were wearing a helmet, then you should be ok. You can re inquire with more information next time . Good luck