Can driving dehydrated really be as dangerous as drunk driving?

“While driving, this means the brain may not process information quickly enough, and the body may not respond as effectively to sudden situations on the road,” she further adds.

But how can you recognise if you are dehydrated? Kholi suggests to look out for common signs such as dry mouth, thirst, headache, dizziness, tiredness, and reduced alertness. “Subtle symptoms like irritability, difficulty concentrating, muscle cramps, or blurred vision can also appear, all of which can interfere with safe driving,” Kohli points out.

Can dehydration impair concentration and reflexes as much as alcohol, and how dangerous is it for driving?

Kohli cautions that dehydration can indeed impair concentration and reflexes in ways comparable to alcohol. “While it may not cause the same level of impairment as heavy drinking, the effects can still be dangerous. A dehydrated driver may drift between lanes, react slower to hazards, or miss important signs, which can put them and others at risk.”

Kohli’s claim is backed by science. A 2024 Behavioural Science & Digital Health trial showed that drivers who are dehydrated have 40% slower reaction times and 50% more missed cues than well-hydrated drivers.
“Just as alcohol impairs judgment, dehydration affects concentration and motor skills,” Kohli explains while drawing the parallel between the two.

“A dehydrated driver may be slower to hit the brakes, misjudge distances, or lose focus, increasing the risk of accidents. This risk is especially high on long trips where alertness is essential.”

Is dehydration normal or a sign of an underlying condition, and when should someone consult a doctor?

While normally dehydration happens when someone is not drinking enough water, especially during long journeys or in hot weather, it may sometimes signal an underlying health issue.

“Frequent or severe dehydration may suggest problems like diabetes, kidney issues, or hormonal imbalances. If someone becomes dehydrated very quickly or repeatedly, it is worth consulting a doctor,” Kohli advises.

Similarly, if there are any unusual symptoms alongside dehydration like “fainting, persistent fatigue, or confusion” a doctor should be consulted. “If a driver struggles to stay hydrated even after drinking water, it may indicate an underlying health problem that requires medical evaluation.”

Thus, even if drinking water before hitting the road may seem insignificant, it is a crucial road safety habit, just like cutting out on alcohol before getting behind the wheel.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.