Hydrocephalus in diseases classified elsewhere

This code signifies hydrocephalus that arises as a secondary manifestation of another underlying disease process, rather than being a primary or congenital condition. It indicates an abnormal accumulation of cerebrospinal fluid (CSF) within the brain's ventricles, where the primary etiology is a distinct, separately classified illness.

Use this code when documentation clearly links hydrocephalus to an underlying disease, such as a tumor, infection (excluding congenital toxoplasmosis), or hemorrhage, and the primary disease is also coded. This code requires the primary condition to be identified and coded first, with the hydrocephalus coded as a manifestation.

• Always sequence the underlying disease first, followed by this code.
• Do not use this code for congenital hydrocephalus or hydrocephalus of unknown etiology.
• Carefully review documentation to ensure the hydrocephalus is explicitly stated as a complication or manifestation of another classified disease.