Yellow Nail Syndrome (YNS) is a rare medical condition predominantly affecting adults over the age of 50, although it can occasionally present in younger individuals or run in families. YNS is characterized by a triad of symptoms: yellow discoloration of the nails, respiratory manifestations such as chronic cough and pleural effusion, and lymphedema in the lower limbs. This syndrome can also be associated with chronic sinusitis. The exact cause of YNS remains largely unknown, but lymphatic dysfunction is frequently implicated. YNS can occur in isolation or be associated with autoimmune diseases, cancers, and other conditions impacting lymphatic function, classifying it sometimes as a paraneoplastic syndrome. Treatment is primarily symptomatic, and in some cases, the condition can resolve spontaneously.
