Navicular syndrome (navicular disease)
Necrotising enterocolitis
Necrotising fasciitis
Nasogastric reflux
Nasolacrimal (tear) duct abnormality (unspecified)
Nasolacrimal duct atresia
Nasopharyngeal collapse (unspecified)
Nasopharyngeal collapse – fixed
Neuromuscular disorder (unspecified)
Neuromyotonia / myokymia