Research has shown that there is a small, long-term risk involved in kidney donation, especially if the donor is a dark-skinned man with a 1% greater risk of complications than the rest of the donors.
The risk of residual renal failure was 1% higher than that of healthy people. If you are a potential kidney donor, you will have a thorough medical examination to determine if you are well-matched with the donor, and you will be subject to this rigorous examination to make sure you are free from any health problems that may worsen with your donation.
The kidney donation involves major surgery, and there are risks of bleeding and infection. After removal, the hospital and home will spend some time recovering. Over time, the remaining kidney will expand as it receives additional blood flow and filters more waste. .
Long-term survival, quality of life, general health and kidney failure are almost the same for those who have not.
Source
https://www.mayoclinic.org/tests-procedures/nephrectomy/expert-answers/kidney-donation/faq-20057997