I have a strange problem with my fingers. I have a habit of cracking knuckles of my fingers of left and right hand both. But this habit has become so serious that I always feel like I should crack my knuckles. Otherwise joints of fingers start paining in a strange way. And it gets relieved only when I crack my knuckles again. Could it be a serious problem? Is cracking knuckles injurious? Please help me to get rid from that habit.