Reflux nephropathy

What causes reflux nephropathy?

Reflux of urine from the bladder up towards the kidneys is common, occurring in more than 1 in 100 new born babies. As the baby grows, reflux usually disappears. This is because the section of the drainage tube from the kidney that lies within the muscular wall of the bladder lengthens during growth. This means that as the bladder squeezes to eliminate urine from the body, it becomes more likely to ‘pinch off’ the ureter and stop any urine refluxing.

Reflux nephropathy is the generally only a problem if there have been infections very early in life that have caused some damage (scarring) to the kidney, or if the reflux does not go away as the baby grows. Only about 1 in 10 babies born with reflux develop such problems. The majority grow up normally, often without anyone knowing that there had been reflux at any time in their lives.

Kidney damage occurs in some people with reflux. The exact cause of the damage is not always clear. Sometimes it seems that a severe infection has damaged a section of a kidney so much that it turns into scar tissue and cannot function normally. The reflux itself may put back pressure on the tissue of the kidney when the bladder is emptying, which might also cause damage. Lastly, some people develop kidney failure from reflux nephropathy in the absence of obvious infections, and also in the absence of ongoing reflux of urine back towards the kidneys. The exact explanation for this is not clear, and it is an area where a lot of research is being carried out.

Reflux caused by other medical conditions

Reflux of urine from the bladder can occur because other medical conditions have affected the junction of the bladder and ureter (tube coming down from the kidney). There are many conditions reported as causing this, but they are not common in the United Kingdom. Irradiation (X-ray therapy) to the bladder, surgery to the bladder or ureter, kidney transplantation, and bladder problems secondary to spina bifida or multiple sclerosis are some of the causes.

The treatment of reflux in these circumstances is similar to that of reflux nephropathy generally. However, the chances of developing severe problems such as kidney failure vary from case to case, and advice should be sought from the medical specialist.

NKF Controlled Document No. 16, What causes reflux nephropathy?, written 28 October 2002. Last reviewed 27 October 2008.

The National Kidney Federation cannot accept responsibility for information provided. The above is for guidance only. Patients are advised to seek further information from their own doctor.

The National Kidney Federation is registered in England and Wales as a Company limited by guarantee (Company No 5272349)
and awarded charitable status (Charity Number 1106735).

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Page created: 28 October 2002

Last updated: 29 April 2009

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