Nephrogenic systemic fibrosis (NSF) is a rare but severe condition that affects the skin and internal organs of people with kidney disease. NSF used to be known as nephrogenic fibrosing dermopathy (NFD), but the name was changed in 2005 to reflect the systemic nature of the disease. Other synonyms for NSF include nephrogenic fibrosing dermopathy, nephrogenic systemic sclerosis, and gadolinium-associated systemic fibrosis. Gadolinium is a contrast agent used in some MRI scans, and it has been linked to the development of NSF in some cases. Despite ongoing research, the exact causes of NSF are still not fully understood.