Why Am I Always Thirsty?

After working out or spending time in the hot sun, it's normal to be thirsty. If you eat salty or spicy foods, your thirst may seem unquenchable. But what about when you're unusually thirsty - when no matter how much you drink, it's just not enough? Should you be worried?

Common causes
Some common causes for extreme thirst - or polydipsia - are:

• Water and salt loss. This may be from sweating, diarrhea, vomiting or lack of water.
• Certain medications.
• Too much alcohol, caffeine or salt.

Possible medical conditions
Your thirst may be a sign of something more serious. You could have one of many conditions, including the following:

• Hyperglycemia (high blood sugar)
• Diabetes
• Diabetes insipidus (an imbalance in the body's water level)
• A kidney disorder (such as Fanconi's syndrome)
• Dehydration
• Liver disease (such as hepatitis or cirrhosis)
• A bleeding disorder (such as intestinal bleeding)
• Burns or an infection
• A head injury
• A psychological disorder (Schizophrenia or obsessive compulsive disorder may cause compulsive water drinking.)

Medications
Certain drugs can make you thirsty. These include:

• Diuretics. Used to treat high blood pressure, diabetes and heart failure. Also used for swelling and diabetes insipidus. They help increase urination and decrease body fluids.
• Demeclocycline. Treats bacterial infections and lowers sodium levels.
• Lithium. Treats bipolar disorder and other mental health problems.
• Phenothiazines. Used to treat schizophrenia and other mental health problems.

Source:

Georgetown University Hospital. Excessive thirst. Accessed November 4, 2006.

This article was reviewed and updated June 2007.