RESEARCHERS have called for a rethink in using the term 'kidney disease' after a study found reduced level of kidney function was a normal sign of ageing.

Researchers from Oxford University, as well as academics from Bristol and Johannesburg called for doctors to replace the term 'chronic kidney disease' (CKD) with different bands of kidney age.

The study, they said, produced a clear link between decreasing kidney health and increasing age.

Lead author, Richard Stevens, associate professor at Oxford University's Nuffield Department of Primary Care Health Services, said doctors were facing an 'uphill battle' to reassure patients once using the word disease.

He said: "Qualitative studies show that communicating a diagnosis of ‘CKD’ to patients can be uncomfortable and unsatisfactory for all concerned, and primary care physicians often face an uphill battle to retrieve the situation with reassurance.

"Some doctors prefer not to mention the condition to patients so as to avoid any unnecessary worry, given that a reduced but stable kidney function in elderly patients requires regular monitoring rather than immediate intervention."

Since 2002 the different stages of CKD have been used to label the rate at which blood passes tiny capillaries in the kidney each minute but the research claims this is more closely linked to age.