Noise in my door

There's a sound kinda like something is loose and bumping around inside my driver's side door near where the door latches shut on the car body...the place where the manufacturer sticker is with the tire pressure and VIN number etc. Can't figure out what it is though, but it might explain why my door is getting harder and harder to open. Soon I might have to crawl into my car...

first do a visual inspection to see if you can find the problem. if you can't see something that is wrong. rip off the door panel and see what falls out or what is loose