People who exhibit extreme thirst and are driven to drink excessive amounts of water suffer from polydipsia, a condition that can result from a number of issues. One of the most common causes of polydipsia is disease, with diabetes being the most frequent culprit. More temporary, environmental-type factors such as being in a very hot, dry location or eating spicy or salty foods can also be to blame. Certain types of drugs or high levels of some supplements can lead to severe thirst. When the condition is the result of a psychological disorder, it is known as psychogenic polydipsia.
A number of diseases, disorders, and medical conditions can all be causes of polydipsia. It is a very common early warning sign of both diabetes mellitus and diabetes insipidus, which lead to frequent urination that depletes the body of water. Another common disease that causes excessive urination leading to dehydration is primary hyperaldosteronism, a disease of the adrenal glands.
Any illness that causes significant fever, vomiting, or diarrhea can quickly dehydrate a person, causing him or her to become extremely thirsty. Injuries or illness that cause significant hemorrhaging or blood loss may decrease fluid levels in the body to the point that the person feels driven to drink to replace them. Polydipsia often accompanies sepsis, where bacteria in the bloodstream lead to a systemic immune response, which can also cause a significant loss of fluids.
Polydipsia can sometimes be temporarily caused by a person's environment or behavior. Being in a climate that is very hot or dry such as a desert, particularly for those who are not accustomed to it, can trigger severe thirst. Hot, spicy foods, or those high in salt, can also be causes of polydipsia.
Medications and supplements are another of the potential causes of polydipsia. A number of drugs used for a variety of disorders can lead to the condition; some examples include naproxen, lithium, and tamoxifen. Too much vitamin D can lead to toxicity, as can overuse of the herb pennyroyal, both of which can be causes of excessive thirst.
In some cases, psychological disorders are the causes of polydipsia. While it may be observed with a number of conditions, it has particularly been observed as a symptom of schizophrenia. The cause in these cases is purely psychological, as patients typically do not suffer from any physiological problem like dehydration that would cause them to need additional fluids. This can become dangerous, as the excess consumption of unnecessary water can upset the levels of sodium in their bodies.
