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.
Abnormal coloring
Redness of the sclera is typically caused by eye irritation causing blood vessels to expand, such as in conjunctivitis ("pink eye"). Episcleritis is a generally benign condition of the episclera causing eye redness. Scleritis is a serious inflammatory disease of the sclera causing redness of the sclera often progressing to purple. Yellowing or a light green color of the sclera is a visual symptom of jaundice. In cases of osteogenesis imperfecta, the sclera may appear to have a blue tint, more pronounced than the slight blue tint seen in children. The blue tint is caused by the showing of the underlying uveal tract (choroid and retinal pigment epithelium). In very rare but severe cases of kidney failure and liver failure, the sclera may turn black. See also
Extraocular implant
Scleral tattooing
Sclerotomy

Notes
References
External links

Histology image: 08008loa – Histology Learning System at Boston University
Atlas image: eye_1 at the University of Michigan Health System—"Sagittal Section Through the Eyeball"
MedlinePlus Encyclopedia: 002295