Here in the U.S., we're fortunate enough to have clean drinking water at our disposal almost at all times. As such, when we're thirsty, we either fill up a glass with some tap water, take a sip from a water fountain, or spend a buck-and-a-half on a bottled water. Whatever method we choose, the end result is the same: we're no longer thirsty.

But what if a glass or bottle of water isn't enough to satisfy your thirst? And, what if you're excessively thirsty all the time? HealthCentral.com reports that this may be a sign of a serious health problem.

Health Central lists the following causes of excessive thirst, courtesy of the U.S. National Library of Medicine:

• A side effect of certain drugs, including anticholinergics, demeclocycline, diuretics or phenothiazines.
• Significant loss of water or salt, possibly caused by not drinking enough water, profuse sweating, diarrhea or vomiting.
• Significant blood loss or loss of body fluids, caused by an underlying health condition.
• Diabetes or diabetes insipidus.