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One kidney (a solitary kidney): the checkups, keeping it safe, and giving a kidney

For anyone born with one kidney, who had one removed, who gave one to someone, or who was just told they have only one, and for the parents of a child with one. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK, part of the NIH) says that if you have only one kidney, that kidney is called a solitary kidney, and that complications are rare. This page passes on, by name, what NIDDK says: what it is and the three main causes; what it can lead to; the urine, blood and blood pressure checkups; telling every provider, pain relievers, and sports; and food, pregnancy, and giving a kidney. It builds the words to say and the questions to ask, and prints a card to keep in your wallet.

A word with a dotted line under it, like this, opens its official definition, quoted from a U.S. government glossary.

Kidneys, bladder or urine, and not sure this is the right page? The pages on this site for bladder infections, kidney stones, blood in the urine, bladder pain, bladder leaks, the prostate, kidney disease and bedwetting, on one list.

This page and its wording were written with AI (Claude) for Scarlet Beast (our AI policy). No doctor or nurse has reviewed it. The facts were read on October 18, 2026 on NIDDK’s (NIH) page Solitary or Single-functioning Kidney (last reviewed October 2020), with the lines on living donors from its Kidney Transplant page (January 2018) and the lines on pain relievers and the pharmacy from its Keeping Kidneys Safe: Smart Choices about Medicines page (June 2018), which was written for people with kidney disease, diabetes or high blood pressure. The first two pages are in Spanish too; the third is in English only, so our Spanish page translates those lines with AI. The numbers (about 1 in 2,000 babies born with kidney agenesis; between 1 in 1,000 and 1 in 4,300 with kidney dysplasia; more than 58,000 living donors and more than 255,000 kidneys removed for cancer between 2008 and 2017; 2 to 3 days in the hospital with the smaller-cut technique; Medicare for 3 years after a transplant) are NIDDK’s. Ours: 911 for trouble breathing, chest pain, or fainting; getting care right away after a hit to the belly, side or back with pain, blood in the urine, or no urine; asking whether the medicines page applies to you; telling every provider about procedures and scans with contrast dye; telling the pregnancy care team, the school and the coach; never stopping a prescribed medicine on your own; asking the transplant center what is covered; 988 when it is too much; health centers when money is tight; and the order of the steps. What we left out: the clinical trials sections, the references, the rest of the kidney transplant page (it is for the person receiving a kidney), the medicine examples on the medicines page, and NIDDK’s outside links. This page saves nothing and loads no trackers.