Jaw problems almost like its double-jointed?

Hi there, i have a jaw that is almost like its double-jointed, when i open my mouth- manly when im eating it sometimes locks into place for a 3 seconds and it also sometimes clicks out of place. its been going on for about 4 years and is very annoying
can i get rid of it? what is the cause? and is it bad and going to lead to arthritics ?