Circadian rhythm disorders are disruptions in the circadian rhythm — a name given to the “internal body clock” that regulates the roughly 24-hour cycle of biological processes in animals and plants. The term
“circadian” comes from Latin, meaning “around a day.” There are several types of circadian rhythm disorders,
including delayed sleep phase disorder, advanced sleep phase disorder, jet lag from traveling between time
zones, and shift work sleep disorders caused by irregular sleep schedules.
What are the symptoms of circadian rhythm disorders? In circadian rhythm disorders, there is a continuous or occasional disruption of sleep patterns. This disruption
is either a malfunction of the internal body clock, or a mismatch between the internal clock and the external
environment regarding timing and length of sleep. As a result, those with circadian rhythm disorders
experience insomnia at certain times and excessive sleepiness at other times. This causes problems functioning at work, school or in social activities.
How are circadian rhythm disorders diagnosed? Diagnosing a circadian rhythm disorder is challenging and often requires consultation with a sleep specialist,
who will help rule out other sleep and medical disorders. Some circadian rhythm disorders are prone to be
misdiagnosed as narcolepsy or co-exist with insomnia or sleep apnea. You may be asked to keep a detailed
sleep diary for several weeks. Overnight and daytime sleep studies also may be needed.
How are circadian rhythm disorders treated? Treatment options vary based on the type of disorder and how severely it is affecting your quality of life.
Behavior therapy: includes standardizing sleep times, getting regular exercise, and avoidingcaffeine and stimulating activities before bedtime
Bright light therapy: 30- to 60-minute treatments toreset the circadian clock
Medications: such as melatonin, wake-promotingagents and short-term sleep aids
Chronotherapy: adjusting sleep times by one to two hours per day to shift the sleep cycle
What is an example of a circadian rhythm disorder?
Shift work sleep disorder (SWSD) affects people who frequently rotate shifts or work at night. These schedules (usually between 10 p.m. and 6 a.m.) go against the body’s natural circadian rhythm, and cause difficulty adjusting to different sleep and wake schedules.
What are the symptoms of SWSD?
The most common symptoms are insomnia and excessive sleepiness. Others include difficulty concentrating, headaches and lack of energy. Not every shift worker suffers from SWSD, but it is important to seek treatment if you are affected to avoid driving accidents, work-related errors, increased sick leave and mood problems.
How is SWSD diagnosed?
If you are a shift worker and experience any of these symptoms, you should talk to your doctor. He or she will take a medical and sleep history, conduct a physical exam and determine if a sleep study, or other testing, is needed.
How is SWSD treated?
Shift workers should be educated on the importance of prioritizing time for sleep. There are many strategies to help you sleep even during the day time such as:
Follow regular bedtime rituals
Keep a regular schedule even on weekends
Get seven to eight hours of sleep daily
Ask your family to create a quiet environment during your sleep time