There is a disorder called "polydipsia" referring to the constant urge to drink water. Usually the presence of polydipsia is an indicator of a greater problem. I have personally seen two types of examples of this disorder.

First type, due to diabetes and dehydration

Sometimes a person's body signals that they need to consume A LOT of water QUICKLY because there is an actual physiological need. Individuals who are diagnosed with diabetes urinate excessively, leading to dehydration. This type of polydipsia is often used to begin testing for and diagnosis of diabetes. My experience with this form of polydipsia comes from a loved one who passed away last year. His polydipsia was caused by diabetes, although numerous other health problems led to his passing. Polydipsia can also be a result of dehydration due to a loss of fluids, especially from caffeine, although in this case polydipsia would not pose extreme health risks.

Second type, psychogenic, often associated with schizophrenia

I have seen this type of polydipsia personally as well while working in the mental health field. The exact causes of this type of polydipsia are unknown. Individuals who have polydipsia as a result of a psychotic disorder are at a high health risk. These individuals will seek water from any source and must be monitored.

The dangers of constant water seeking and drinking

One who drinks water constantly runs the risk of throwing off the body's balance and depleting many important elements such as electrolytes. Polydipsia in the extreme form can be life threatening. Polydipsia can eventually lead to a heart attack or seizures. in the earlier stages polydispsia can dilute and decrease absorption of medications that may be treating serious medical problems or mental illness.

Could I have polydipsia?

Generally if a person drinks a lot of water because they are health conscious it is very unlikely that they would be able to drink so much water that they would experience any of the health risks mentioned above. However, if you feel a constant urge to drink water and believe it is possible that you have diabetes, you may consider speaking to a physician as soon as possible. Countless problems can arise from late diagnosis of diabetes.