Sunday, November 11, 2007

Drowsy Driving

The National Sleep Foundation's first annual Drowsy Driving Prevention Week (DDPW) is November 5th through 11th.

Each year, crashes due to drowsy driving result in at least 1,550 deaths and 71,000 injuries.

One of the most common causes of sleepiness while driving is voluntary insufficient sleep. Although a majority of us have the physiological ability to obtain the 7.5 to 8.5 hours (up to 9.5 hours in teenagers) of sleep necessary each night to feel fully rested - work, school, and family pressures often make it difficult to find enough time to sleep. Alcohol, when combined with sleep deprivation, can be particularly deadly.

Other causes of sleepiness include disrupted sleep (from obstructive sleep apnea or other sleep disorders), medication effect, circadian rhythm disorders (more about these below) and medical conditions that directly cause sleepiness (e.g., narcolepsy). After insufficient sleep, obstructive sleep apnea is the most common cause of daytime sleepiness. Many medications, including anti-seizure medications and many psychiatric medications, can also cause drowsiness.

Circadian rhythm disorders are conditions in which the body's 24 hour clock is out of alignment with the environment, producing insomnia and/or sleepiness during unusual hours. Examples include delayed sleep phase syndrome and shift work sleep disorder. In delayed sleep phase syndrome, which is common among adolescents and young adults, the main sleep period is delayed. A typical sleep period with this disorder would be from 3 am to 11 am. Insomnia occurs if the person tries to sleep outside this time bracket. If the person needs to get up early for work or school, sleepiness will occur. Insomnia and sleepiness are also common in shift workers, especially if the shifts are rapidly rotating.

It is important to allow sufficient time in your schedule for sleep. If you feel sleepy despite obtaining 8 hours at sleep at night, consultation with a physician is recommended. Also, talk to your doctor if insomnia prevents you from obtaining the necessary amount of sleep to feel fully rested.

Do not drive if you are feeling drowsy. If you become drowsy while driving, pull over and take a break (and a nap, if possible). Caffeine can have a mild effect in improving alertness.


lrubin39 said...


I host a blog and the subject of sleep apnea has come up again. (

Would you be interested in assisting by either posting an entry, answering questions, or any idea you may have?

You can also email me at

Michael Rack, MD said...

thanks for the invite.
I posted a comment on your If I should Die before I wake post