Recently my thumb has been swelling up alot lately.  I got my thumb hole re-drilled and opened up and it worked for 2 nights.  The next week it swelled up again to the point where the thumb didnt fit into the newly redrilled thumb hole.

Here's a pic comparing both my right (normal thumb) to my left (not-so normal thumb)
http://i1359.photobucket.com/albums/q799/MDS826/photo.jpg

Any ideas on what caused this and what I should do?

Thanks,

MDS

*Drilling an oval thumb hole to fit your thumb specifically.
*Checking the thumb pitches to ensure it allows you to release the ball without grabbing

Thumb and finger pitches and span.  Loose thumb etc etc.  Most bowlers have never felt correct fit.

I had a similar problem with my thumb. The oval-drilled hole really helps.

So I went with a 45 degree drilling with oval shape.

Bowlgnut...can you explain what 45 dgree drilling is?

This basically indicates that the wide measurement of the oval thumb hole is set at 45° to the grip line running from between the finger holes to the center of the thumb hole.

Thanks jmac

As stated above you should get your thumb hole redrilled to fit better.  I also recently started to get swelling on the left side of my thumb.  After years of never having any problems it just seem to start for no reason. 

However, after checking my thumb was one inch wide left to right however from nail side to pad it was only 3/4 of an inch.  Using tape on my thumb would show rub marks where it was rubbing and where it ended on the side was where I started getting the swelling.

After getting the thumb hole made into an oval my thumb swelling went down because I must not be bending my thumb trying to hold on with a hole fit for the sides not nail to pad which was to big.

I also had my angle checked from the mid grip line to the angle where the sides of my thumb touched the sides of the thumb hole and it was 65 degrees, so everyone may be different. This was checked because I was having an interchangeable thumb unit installed so I could move the thumb hole unit from ball to ball and always have the same exact hole and fit.  It has helped the swelling go away because the hole is now an oval and it just fits better and helps keep my thumb straight, no wiggle room to knuckle the ball and cause problems.

Good luck.