Middle finger joint seens to move out of place

[Mrenon]

My right hand middle finger joint (the one between the first and second phalanges seens to dislocate or move out of place when I press it with my thumb. It seens to pop although I can´t hear any sound, unless I´m holding it very close to my ears. It occurs when I press the left side of the joint ( the one closest to my index finger) using my thumb. I don´t know if it is the bone or some kind of ligament or tendon that is actually moving, but I can fell something moves out of place. I don´t feel any kind of pain and the joint seens to be working properly. Also when I flex my finger and touch the low side of the joint (the one on the same side as the palm) using another finger I can feel what seens to be a tendon poping, although I also can´t hear any sound. I think It´s necessary to mention that about three to four years ago ( I´m 19 now) this same finger became a little red, swollen and painful for about three days, for no aparent reason but afterwards it was back to normal and I never had any more pain on it. This finger seens to be a a little larger than my left hand one. Their width is about 1,9mm and 1,8mm respectively. ( I measured them using a ruler). I would like to know what could be happening to my finger and if it could be something serious like arthritis. I would like to mention again that I don´t fell any pain in the joint and that It´s a little swollen but I presume It´s because I pressed it a lot using my thumb(it became some kind of addiction to do this).

[Mrenon]

Thank you very much for your reply. I´m much relieved now. I will keep watching it and follow your instructions if any problem happens. Thank you very much again.

[Dr Vinod]

It is not an arthr"itis", as any "itis" is an inflammation and it is painful. Bones are joined by ligaments and at this place your  bone from the ligament is popping out when you move it with your hand and again is slipping inside.
As it does not cause pain and you do not have problem you can neglect it, but if it comes on the way of your day to day activities you should go for an X-ray and also visit an Orthopaedician to assess the case.
Take care!