People with non-24-hour sleep-wake syndrome do not have internal clocks that reset and stay balanced within a 24 hour schedule. In most cases, their circadian rhythms are set on longer loops, usually resulting in 25 or 26 hour cycles, or even more in some cases. There have been documented cases of people having as dramatic as 72 hour cycles, in which they would stay awake for 48 straight hours, and then sleep for 24 straight hours as a regular sleeping pattern. There are only a few known dramatic cases such as that though, and most cases fall within the 25 or 26 hour range.

What this means for these individuals is that their sleep and wake times are pushed back by 1 or 2 hours every day. This leads to a constant cycle between sleep times that are considered unconventional by society’s standards, with occasional short stops in conventional time frames before progressing on again into unconventional. This extremely unbalanced sleeping schedule makes it all but impossible for the subject to hold a traditional job, or attend regularly scheduled school classes unless they fight the disorder, which is not easy without the proper treatment. Individuals living with this have often found their “calling” working in a self employed capacity, or in a number of other fields of work where they can effectively set their own work schedule. Those still attending school may find it necessary to take home schooling through the internet or other avenues.

Apart from the social stress or depression that living with this disorder may cause, the disorder itself is not considered harmful. The actual quality of sleep, and more importantly deep sleep, is equal or in many cases better, than those without the disorder. For instance, Kamato Hongo was one of the oldest living person in the world (who died at age 116), known also for  for her habit of sleeping for two days and then staying awake for two days.

This disorder is very common among blind people, with more than 50% of blind people having it. Though they have fully functioning biological clocks, without the light cues to balance and reset it on, the circadian rhythm often becomes unbalanced. This condition is quite rare in those with sight, but can occur. Having unstructured or irregular daily routines, bad sleeping habits, and poor exposure to sunlight on a consistent basis can all be factors in the development of this disorder.

Light Therapy

Once the disorder has been diagnosed, the treatment plan can begin. The first step will target changes you can make in your routine in an attempt to reset and balance your circadian rhythm. This will include incorporating fixed events into your schedule at set times no matter when you wake up, to try and root your internal clock to a 24 hour rhythm.

Melatonin is the most widely used treatment, and is typically ingested within a few hours of the desired bedtime. This can be helpful in rooting your bedtime. Light treatment (see picture above) for sighted people, in which patients are exposed to high intensity light for a duration of 30–60 minutes at a time, and chronotherapy, in which the patient advances or delays the sleep time by 1–2 hours per day, can also be used as well.

Reference: The American Sleep Association