These include:

The distinction between CRS type 2 and CRS type 4 is based on the assumption that, also in advanced and chronic disease, two different pathophysiological mechanisms can be distinguished, whereas both CKD and HF often develop due to a common pathophysiological background, most notably hypertension and diabetes mellitus. Furthermore, the feasibility of the distinction between CRS type 2 and 4 in terms of diagnosis can be questioned.Braam et al. argue that classifying the CRS based on the order in which the organs are affected and the timeframe (acute vs chronic) is too simplistic and without a mechanistic classification it is difficult to study CRS. They view the cardiorenal syndrome in a more holistic, integrative manner. They defined the cardiorenal syndrome as a pathophysiological condition in which combined heart and kidney dysfunction amplifies progression of failure of the individual organ, by inducing similar pathophysiological mechanisms. Therefore, regardless of which organ fails first, the same neurohormonal systems are activated causing accelerated cardiovascular disease, and progression of damage and failure of both organs. These systems are broken down into two broad categories of "hemodynamic factors" and non-hemodynamic factors or "cardiorenal connectors". Management
Medical management of patients with CRS is often challenging as focus on treatment of one organ may have worsening outcome on the other. It is known that many of the medications used to treat HF may worsen kidney function.
Cardiorenal syndrome (CRS) is an umbrella term used in the medical field that defines disorders of the heart and kidneys whereby "acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other". The kidney and the heart are compared to a marriage that has "bumps" in the road, some may even say it can come to an end. The heart and kidney play vital functions that contribute to the wellbeing of the body in a healthy person. When one of these organs fail, the other subsequently fails as well, like a domino affect. The heart and the kidneys are involved in maintaining hemodynamic stability and organ perfusion through an intricate network. Patients who have renal failure first may be hard to determine if Heart Failure is concurrent. These two organs communicate with one another through a variety of pathways in an interdependent relationship. In a 2004 report from National Heart, Lung and Blood Institute, CRS was defined as a condition where treatment of congestive heart failure is limited by decline in kidney function. This definition has since been challenged repeatedly but there still remains little consensus over a universally accepted definition for CRS. At a consensus conference of the Acute Dialysis Quality Initiative (ADQI), the CRS was classified into five subtypes primarily based upon the organ that initiated the insult as well as the acuity of disease. Signs and symptoms
Risk factors
The following risk factors have been associated with increased incidence of CRS.