Sleep disorders not due to a substance or known physiological condition (F51)

ICD-10 codes in the F51 section are used to classify sleep disorders that are not caused by substance use or identifiable physiological conditions. This range covers various forms of insomnia, hypersomnia, and parasomnias like sleepwalking and night terrors, helping healthcare providers specify nonorganic sleep problems.

The F51 codes assist in recognizing conditions such as primary insomnia (also called nonorganic insomnia or hypersomnia of non-organic origin), which involves difficulty sleeping without an external cause. Adjustment insomnia (transient insomnia) and psychophysiologic insomnia (chronic insomnia) are included under this section. It also covers hypersomnia types, including primary hypersomnia and insufficient sleep syndrome, where trouble staying awake or getting adequate rest occurs independently of other disorders. Parasomnias like sleepwalking (somnambulism), sleep terrors (night terrors), and nightmare disorder are coded here to specify these unusual sleep behaviors. The section's “other” and “unspecified” categories allow coding of less common or poorly defined nonorganic sleep disorders. These codes help medical coders identify non-substance-related sleep disturbances precisely, facilitating accurate diagnosis and treatment tracking.