Kidneys are strange organs. They have multitude of roles, extending much further than the filtering of blood they are most commonly known for. As well as excretion of waste products, they have a large role in maintaining the base conditions inside of your body; regulating blood pressure, acidity, and the concentration of your blood (to learn more go here 1). Because of these roles your kidneys receive about 20% of all the blood pumped by the heart, that’s more than the amount that goes to your brain.

Perhaps because of they widespread uses, they’re also hit by a large number of diseases. The most common causes of end-stage renal disease in the UK are diabetes, high blood pressure, and an inflammatory condition called glomerulonephitis, such that at any one time around 34,000 people are being treated for ESRD at any one time2.

One option for these people is dialysis, which functions essentially as an artificial kidney, usually requiring blood to be passed through as machine which removes waste products through osmosis. However dialysis is far from a perfect solution. Despite advances in the 70+ years since its invention, its simply not as effective as an actual kidney. For some time now, since the advent of effective immunosuppressive medications, the best treatment has been kidney transplantation.

Patients who receive a kidney can be expected to live over 10 years longer than similar patients on dialysis, and the effects are more pronounced the earlier the transplantation, and the younger the patient3.

However at any one time there are around 5000 people waiting for a kidney in the UK alone, and 250 people die each year while waiting. Even though rates of transplantation continue to increase, with approximately 3000 transplants performed each year, adults can expect to wait over 2 years for their kidney4. Given that the earlier the transplant the more favourable the outcome, this is time that matters. There’s also an important distinction between living and deceased donor kidneys, with the former often lasting about 5 years longer.

Another interesting fact about kidneys is that we can live with only one of them just fine. In fact some people can go their entire lives not knowing their lack due to a embryological quirk. In fact studies into the long-term consequences of living kidney donors found lower rates of ESRD among donors than in the baseline population5. Before anyone cries foul just yet, while it is true that donating a kidney increases your personal risk of ESRD, because of the prior screening and verification of health, your personal risk is still likely less than that of the general population. On top of this it even saves healthcare authorities money.

In 2006, with the crowning of the Human Tissue Authority, it became legal for people to donate kidneys to people they didn’t know or hadn’t met. The first of these non-directed donations was carried out a year later in 2007 at the Royal Free Hospital in London. Since then rates of non-directed have increased, and at around the 10 year anniversary of the first non-directed donation there have been over 580 of these operations carried out in the UK.

While this is a relatively small number compared to those donated by friends and relatives, altruistic kidneys fill an important gap particularly for those whose relatives are unsuitable donors. They can also kick off a chain of donations in which a patient’s friend or relative donates to a stranger in return (see image).

A Kidney Donating Chain. Credit www.kidneylink.org
A Kidney Donating Chain. Credit www.kidneylink.org

In short, the growing movement of non-directed kidney donation could play an important role in the management of renal disease, especially as the prevalence of the precipitating factors such as diabetes and hypertension continues to increase. For those thinking about becoming a living donor, I would strongly urge visiting the NHS Organ Donation site to find out more.


  1. https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-the-kidneys/v/meet-the-kidneys 

  2. http://www.kidney.org.uk/documentlibrary/Press-Guide.pdf 

  3. http://www.bidmc.org/Centers-and-Departments/Departments/Transplant-Institute/Kidney/The-Benefits-of-Transplant-versus-Dialysis.aspx 

  4. https://nhsbtdbe.blob.core.windows.net/umbraco-assets-corp/4496/section_5_kidney_activity.pdf 

  5. https://www.ncbi.nlm.nih.gov/pubmed/15240849