In general, people operate on a 24-hour biological clock, also known as the circadian rhythm, which is in sync with natural light, darkness, and bodily hormone production. The circadian rhythm plays a major role in numerous physiological processes, including sleep, body temperature, eating, digestion, and hormonal activity.

This rhythm resets every 24 hours based on light and darkness cycles making a healthy person wake up in the morning when it’s light and feel sleepy in the evening when it’s dark. However, the circadian rhythm can sometimes suffer from dysfunctions or misalignments that lead to circadian rhythm sleep disorders.

Now, if you wonder whether you suffer from such a disorder, continue reading and find out everything you need to know about circadian rhythm sleep-wake disorders.

Circadian Rhythm Sleep Disorders

1. 1. Delayed Sleep-Wake Phase Disorder

This disorder is characterized by 2+ hours pushed back sleep-wake cycle. The main symptoms include having difficulties falling asleep at night and waking up earlier in the morning. As a result, people with the disorder, known as night owls, suffer from a chronic lack of sleep especially if they require an early wake-up time due to school or work.

2. 2. Advanced Sleep-Wake Phase Disorder

Contrary to the first one, people with advanced sleep-wake phase disorder fall asleep and wake up at least two hours before their ideal times. So, these people, referred to as early birds, also suffer from a lack of sleep, especially if working night shifts. Plus, advanced age is a risk factor for advanced sleep-wake disorder.

3. 3. Irregular Sleep-Wake Disorder

Inconsistent sleep patterns and a lack of stable day-night cycles are the main characteristics of this disorder. Such abnormal sleep patterns lead to excessive daytime sleepiness and trouble sleeping. Typically, the disorder is common in those who suffer from a neurodevelopmental or neurodegenerative disorder like Alzheimer’s, Parkinson’s, or Huntington’s disease.

4. 4. Non-24-Hour Sleep-Wake Rhythm Disorder

Non-24-hour sleep rhythm disorder, known as a free-running disorder, happens because the internal clock doesn’t reset every 24 hours as it should. So, the normal sleep period is constantly changing in people with this disorder. Symptoms include insomnia and daytime sleepiness but the severity depends on the person’s daily schedule.

5. 5. Shift Work Disorder

People who do night shifts, either partly or completely, know how difficult it could be to get a good night’s sleep. Shift work disorder is characterized by excessive daytime sleepiness and insomnia. In addition, shift workers usually lose one to four hours of sleep every day and have a higher risk of accidents.

6. 6. Jet Lag

Last but not least, jet lag is yet another circadian rhythm sleep-wake disorder that occurs after flying over multiple time zones. The condition is characterized by temporary sleep disturbances and extreme daytime fatigue during the transition period in which the internal clock needs to get in sync with local time. The symptoms start after one to two days and may last a week or two.

The bottom line, all of the above-listed disorders can be pretty challenging to deal with. Therefore, make sure you follow good sleep hygiene practices and a consistent sleep-wake schedule to improve entrainment and reduce sleep deprivation. Plus, if you suspect you have one of those, ensure you consult your doctor or a sleep specialist to get the right treatment option and relieve your symptoms.