Klein-Levin syndrome versus bipolar disorder not otherwise specified- diagnostic challenges.

Hypersomnia presents as excessive daytime sleepiness with a prevalence of 7.1% in general population. Hypersomnia has serious negative effects on persons functioning. The aetiology of hypersomnia can be due to neurological conditions, primary sleep disorders, Substance induced, Psychiatric disorders and idiopathic. Klein-Levin syndrome (KLS) is condition characterised by hypersomnia, hyperphagia and hypersexuality. Among the psychiatric disorders, hypersomnia is seen in bipolar depression. In bipolar disorder, hypersomnia can be present during the depressive episode and also inter-episodically. Here is a case report on hypersomnia and diagnostic challenges.