I enjoy teaching in my practice, and often have medical students and residents rotating with me. One of the main things I teach these students is how to recognize dehydration, because patients can suffer a rapid decline in health — even leading to death — if they are dehydrated.

The most obvious sign of dehydration is excessive thirst, which may be accompanied by a dry, sticky mouth with a tongue that appears almost carpet-like. (By the end of a month observing patients with me, all of my students have developed the habit of looking into a patient’s mouth and describing whether the tongue looks like a piece of carpet versus being pink and moist.)

Other symptoms that can accompany dehydration include fatigue, muscle aches, and other pains.

One of the most common signs of dehydration is headache. The primary constituent of the brain is water. It needs adequate water to function correctly. A dehydrated brain will often hurt, and fail to function properly. That is, a person will not think clearly.

As dehydration worsens, it can lead to delirium or unconsciousness.