Multifactorial chronic kidney disease and the kidney capacity-workload balance.

Chronic kidney disease (CKD) is defined by the presence of kidney abnormalities with an impact on health that lasts more than 3 months. Cross-sectional population data suggest that ~10% of the world population might be affected. CKD is often classified by aetiology, under the assumption that a single cause drives disease, and identifying the single cause that drives kidney disease in a patient is a key nephrology expertise taught at medical schools. Here, we explore the concept that, throughout the life-course, the kidneys are exposed to numerous insults and risk factors that can trigger CKD development and reduce kidney lifespan. Although a single cause might be dominant in some individuals, CKD frequently results from exposure to several serial insults or multiple concomitant factors; hence, CKD is typically multifactorial. The concept of multifactorial CKD not only better matches the clinical reality but also has numerous clinical implications, including for diagnostic work-up and kidney-disease nomenclature, as well as therapeutic choices (for example, the choice between cause-directed therapies versus lifestyle changes and CKD combination therapies). In addition, the risk factor-based concept of multifactorial CKD provides a strong rationale for risk factor control to maintain kidney health.