(HealthDay News) -- An occasional glass of water should satisfy most cases of thirst. But if it seems like you're excessively thirsty all the time, it may be a sign of a serious health problem.

Here are common causes of excessive thirst, courtesy of the U.S. National Library of Medicine:

• Significant blood loss or loss of body fluids, caused by an underlying health condition.
• Diabetes or diabetes insipidus.
• 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.