HappyPuppet

You will get an evaluation to estimate your risk of developing kidney disease in the future. A lot of variables go into this: your age, race, current level of kidney function, blood pressure, whether or not you have diabetes and the level of protein in your urine.

This is put into a calculator to determine your risk assessment score. They also look at your urine under the microscope to ensure there's nothing suggestive of undiagnosed kidney disease. An ultrasound or other imaging is also performed to make sure you have two normal sized kidneys (some people are only born with one)!!

They also make sure you aren't being coerced and there's no other obvious ethical/legal concerns (I.e, you are selling your kidney).

You can have some medical conditions, but many (such as uncontrolled blood pressure) will disqualify you. Basically, they are looking out for you, the donor, to minimize the chance you develop problems from donation down the line. If you pass the eval it means your risk is minimal (but not zero!) and you're set to give someone a great gift. :)

Did you have a strong family history of colon cancer or other malignancies? Anyone diagnosed at a young age?