Last night when I lay down in bed I felt pain in my index finger of right hand. Sometimes i felt in right side of finger from up to down or sometimes on bottom side of finger. It was very painful. Somehow, I slept. Today when i woke up in morning pain was gone. But I noticed little swelling on bottom(below PIP ,above MCP) of finger. Now in afternoon I am again feeling pain on bottom(below PIP joint Above MCP) side of finger. When i press PIP joint, It hurts. I didn't hit my finger any where. No nausea. What could be the reason of pain?