Right hand middle finger. when i stretch my hand then make a fist if i feel my knuckle there is a thin raised line that moves that isnt on other hand?

Tendon sheath: Based on your description alone, it sounds as if you have what is called a "Boxer's knuckle". It often affects the middle finger, and can happen to "non-boxers", I am a ringside physician, so I see this fairly often. It is due to an injury to the tendon sheath over the knuckle. When you make a fist the tendon slips to the side. If it hurts, see your Dr. (preferably sports med or hand/ortho Dr)