Delayed Sleep Phase Syndrome

Last Updated: August 28, 2018

Definition - What does Delayed Sleep Phase Syndrome mean?

Delayed sleep phase syndrome is when a person's normal sleep/wake cycle is disrupted by two hours or more on a repeated basis and results in fatigue or other sleep deprivation symptoms. For example, if a person works an extra 3 hours several times a week at night and their sleep is delayed due to that work. Alternately, if a person works extra early hours and must wake up earlier than normal, this can also result in delayed sleep phase syndrome.


Delayed sleep phase syndrome does not always pose significant problems for adults but can be a concern in safety sensitive positions.

WorkplaceTesting explains Delayed Sleep Phase Syndrome

Delayed sleep phase syndrome affects up to 16% of the population. It becomes a problem for everyone around the individual when the lack of sleep causes the person to become disruptive or excessively sleepy during work hours. If a person does not have full functioning of all mobility and thought processes, mistakes can be made. Some mistakes can lead to physical accidents.


When the condition lasts for a significant amount of time it is considered delayed sleep phase disorder. Of all the circadian sleep disorders, this is the most prevalent. It is also responsible for 10% of documented insomnia cases.

Share this:

Connect with us

Email Newsletter

Join thousands of employment testing and employee wellness professionals.