Why the cam of my Iphone keeps freezing every time i try to record a video?

I will try to record a video and it won't let me, it stuck like it takes a photo and then freezes

You should definitely try to give us all the info you have on this. What kind of iPhone? Have you tried anything to fix it? What version of IOS are you running? Did this just start happening? And is it just when you try to take a video? From what you said you may want to try a restore through iTunes.

I agree with Gregory… Plus, we do not know how much available space there's on your iPhone. Not enough space = no where to store stuff, including video…