Driving while drowsy is a serious public health problem. At least 100,000 car and truck accidents each year in the U.S. are caused by sleepy drivers. The crashes result in 75,000 injuries and 1,500 deaths. The related monetary loss is estimated to be $12.5 billion per year.

When a driver falls asleep at the wheel, the accident is usually more severe than a fender-bender. This is because in general:

• The accident happens on a high-speed road at 55 mph or above.
• The driver does not attempt to avoid crashing. The driver simply falls asleep and does not brake or steer.
• The vehicle wanders into an oncoming lane or leaves the road completely.

Sleep disorders are one of the key factors that can increase the risk of sleep-related vehicle crashes. This is why it is so important to seek treatment if you suspect you or a loved one has a sleep disorder such as sleep apnea or narcolepsy.

Here is the complete list of factors that increase the risk of drowsy driving and related accidents. These factors have cumulative effects, so that a combination of them substantially increases crash risk.

• Sleep loss (not getting enough sleep).
• Untreated or unrecognized sleep disorders, especially sleep apnea and narcolepsy.
• Driving patterns, including

          -- Driving between midnight and 6 a.m.
          -- Driving in the mid-afternoon hours (especially for older persons).
          -- Driving a substantial number of miles each year and/or a substantial number of hours each day.
          -- Driving for longer times without taking a break.

• Use of sedating medications, especially prescribed anxiolytic hypnotics, tricyclic antidepressants, and some antihistamines.
• Consumption of alcohol, which interacts with and adds to drowsiness.

There are three groups who are especially at risk of causing vehicle accidents due to drowsiness:

• Young people (ages 16 to 29), especially males
• People with untreated sleep disorders such as sleep apnea and narcolepsy
• Shift workers whose sleep is disrupted by working at night or working long or irregular hours

Before you get behind the wheel, here are ways to help avoid becoming drowsy while driving:

• Plan to get sufficient sleep
• Do not drink even small amounts of alcohol when sleepy
• Limit driving between midnight and 6 a.m.
• Seek treatment for any actual or suspected sleep disorder such as sleep apnea and narcolepsy

If you are driving, and start to feel sleepy, it is very important to take preventive action:

• Switch drivers. Let a more alert passenger take over.
• Stop and sleep. On long-distance trips, quit driving for the night and get a motel room. If this is not possible, stop as soon as possible in a safe area, and take a short nap of at least 15 to 20 minutes.
• Consume around 200 mg of caffeine in one of the following forms:

          -- One 200 mg caffeine pill (NoDoz, Vivarin)
          -- Two 8 fl. oz. cups of regular (caffeinated) coffee
          -- Five 8 fl. oz. cups of black tea
          -- Ten 8 fl. oz. cups of green tea
          -- Three 12 fl. oz. cans of energy drinks (Red Bull, Jolt)
          -- Five 12 fl. oz. cans of caffeinated soda (Pepsi, Coke)
          -- CAUTION: Some medical conditions restrict or prohibit caffeine intake. Consume caffeine only if it is not contraindicated by other medical conditions.

The effectiveness of any other steps to improve alertness when sleepy, such as opening a window or listening to the radio, has not been demonstrated.