There are several types of CRSDs. They include delayed sleep phase, advanced sleep phase, jet lag, shift work disorder, free-running and irregular sleep-wake type. All types stem from the fact that our tendency to be sleepy or alert is to some degree regulated by a part of the brain that acts like a clock. This “clock” is reset on a daily basis by exposure to bright light and other regular activities such as meals or exercise. CRSDs occur when the sleep-wake cycle of our internal “clock” is different from the sleep-wake schedule we would like to follow.

CRSDs can make it harder for you to get high-quality, refreshing sleep. Untreated CRSDs and increased sleepiness can increase your risk of accidents such as car crashes. They may also raise your risk of having heart attacks and diabetes. CRSDs may lead to poor work performance, social stresses and depression.

You may have a CRSD if you find it hard to fall asleep during “normal” sleep times and you are sleepy at times when you should be awake. If your sleepiness is causing difficulties with work, school, or socially, you should be evaluated by a sleep specialist. Before seeing the sleep specialist, keep a detailed sleep history and a sleep log for 1 to 2 weeks. This will help the specialist determine if your sleep problem is from a CRSD or due to another sleep disorder or medical issue.

Treatment varies depending on the specific CRSD. The goal of treatment is to fit your sleep pattern into a schedule that allows you to meet the demands of the lifestyle you want.

Therapy usually includes several approaches:

Allowing enough time for sleep

Keeping regular bedtimes and wake up times (including days off)

Adjusting your wake-up time until you can fall asleep at the time you want

Avoiding taking naps if you have difficulty falling asleep at your desired bedtime

Sleeping in a dark, cool, quiet room

Avoiding caffeine and alcohol within six hours of bedtime

Taking melatonin (available over the counter) may be helpful in certain situations as recommended by your healthcare provider

Using bright natural or artificial light soon after your desired wake-up time, and scheduling meals and activities at regular times to help reset the sleep-wake cycle but avoiding bright light near bedtime.

Having good sleep habits will improve your CRSD symptoms; to keep regular wake-up times and bedtimes.

It is especially important to get evaluated if your sleepiness is affecting your safety such as falling asleep while driving or you’re your ability at work.


For more information contact Grupo HPA Saude on + 351 282 420 400.