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Sniffling and Driving: A Dangerous Mix

Driving with a cold may be as dangerous as driving drunk.

hands on a steering wheel

Driving with a cold may make you a hazard on the highway. The problem isn’t just that you’re looking for a tissue when you should be watching the road. Driving under the influence of a cold may also reduce your ability to detect and avoid an impending crash.

Psychology professor Andrew P. Smith at Cardiff University in Wales has conducted much of the research in this area. In a study by Smith using a driving simulator, volunteers with a common cold were more likely than healthy volunteers to follow the car in front of them too closely.

Cold sufferers also reacted more slowly to road hazards. In one simulated scenario, a pedestrian stepped into traffic, and the driver had to brake quickly to avoid impact. None of the healthy volunteers hit the pedestrian, but more than half of sick ones did. The slowing of reaction times was comparable to driving at the legal limit for alcohol, according to Smith.

Runny Nose Risks

Having a cold may impair your driving by:

  • Affecting your immune system. High levels of proinflammatory cytokines—inflammation-promoting proteins released by cells of the immune system—have been linked to “sickness behavior.” This pattern of behavior helps your body heal when a cold or other infectious illness strikes. But some effects—such as drowsiness, psychomotor slowing, and poor concentration—are decidedly less helpful for driving.
  • Amplifying the effects of fatigue. An earlier study by Smith showed that sluggish reactions and decreased alertness caused by a cold grew worse over the course of a long workday.
  • Leading you to take sedating medicines. Some antihistamines and decongestants can cause drowsiness as a side effect. In the United States, the National Highway Traffic Safety Administration blames 100,000 traffic accidents per year on drowsy driving—and that’s probably just the tip of the iceberg.
  • Disturbing your sleep at night. Symptoms such a stuffy nose and coughing make it harder to get a restful night’s sleep. That’s another possible cause of drowsiness behind the wheel.
  • Making you have a sneezing fit. When you sneeze, your eyes automatically squeeze shut. That’s obviously inconvenient when you’re trying to navigate through a tricky traffic situation.

Running No Risk

If you’re sneezing or coughing a lot, staying home lets you rest and may spare others from being sprayed with your germs. If you do go out, studies suggest that it’s smart to let someone else drive when you can. Take particular care not to drive when drowsy. And don’t rummage around for a cough drop when you need your hands on the wheel.

Linda Wasmer Andrews is a writer who specializes in health, psychology, and the intersection between the two. Follow her on Twitter or Facebook.