Joe Mauer of the Minnesota Twins has a clogged kidney. Not your usual baseball injury, but it's interesting nonetheless. Joe had surgery at the vaunted Mayo Clinic, which makes sense since he's in Minnesota.

The press reports haven't noted Joe's exact condition, but they did mention one critical point. Twins' General Manager Bill Smith said:

It's something he's had since birth. It is something that has bothered him more lately. Everything went fine and he will be ready for the season.

Bingo. 

The most common cause of a kidney obstruction when you're a child is called ureteropelvic junction obstruction. Don't let the big words scare you. All this means is that ureter, which connects the kidney to the bladder, is blocked. This usually is due to genetic abnormality, though it can be caused by various other problems. When this happens you end up with something called hydronephrosis, which is urine backing up into your kidneys. It's like reflux of the kidneys. Hydronephrosis is a very painful condition that can caused lasting, long term kidney damage due to the pressure differences between the kidneys and bladder. 

Now, is this what Joe Mauer had? I have no idea, but a persistent problem from childhood is normally this issue. The kidneys and the bladder system are extremely sensitive to changes in operation, meaning that you well always feel when something isn't working properly. Just ask someone who has had kidney stones. 

Speaking of stones, it is a possibility that Joe Mauer has had a form of kidney stones since youth that caused problems from time to time. Again, there isn't enough information to determine the causes, but stones remain a possibility. 

Do you have a ureteropelvic junction obstruction? More than likely not. The condition is almost always caught after birth and in early childhood. The best way to check is dye solution running through your body. The doctor will take xrays or cat scans of the contrast dye to see if there is blockage. 

What could your kidney pain be? In most healthy adult, kidney pain is caused by kidney stones. God help you if you have them. Of women who had had both a natural child birth and kidney stones they say the kidney stones hurt worse.