12 Most Bizarre Sleep Disorders
Non-24-Hour Sleep-Wake Syndrome
Most people have a sort of built-in body clock that is closely tied to the 24-hour day. But the body clocks of people with non-24-hour sleep-wake syndrome - one of the rarest of all sleep disorders - are out of whack. For example, someone on a 72-hour cycle might be awake for a full 48 hours and sleep for 24. Interestingly, the disorder often affects the blind.
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