It is normal to feel thirsty at various points throughout the day, especially after eating salty foods and after exercise. According to Heinz Valtin, M.D., a professor at Dartmouth Medical School, you will begin to feel thirsty when your blood concentration level has risen by less than 2 percent. Drinking a glass of water should alleviate your thirst in most cases. If you are drinking adequate amounts of water and still feeling thirsty, you may have a health condition requiring medical evaluation.
Foods That Cause Excessive Thirst
Eating a salty or spicy meal may cause a strong urge to drink. Your kidneys regulate body fluid volume. Eating salty food increases sodium concentrations in your blood relative to water. Water found in and around your cells moves into your bloodstream to restore the sodium/water balance. Your kidneys remove the excess sodium and water by excreting them in urine. This process triggers a chemical reaction to prevent dehydration by inducing thirst to replenish lost water. Because they slightly increase your body temperature, metabolism of spicy foods requires extra water, which is why spicy foods make you thirsty, according to "Physiological Reviews." Some medications may also cause excess thirst, especially diuretics, phenothiazines and anticholinergics.
You may become dehydrated due to exercise, a fever, having diarrhea, drinking alcohol or taking certain medications. Symptoms of dehydration include decreased urination, a dry mouth, fatigue, headache, constipation and dizziness. As dehydration progresses, you may have very dry mucous membranes, no urination at all, a lack of perspiration and rapid heartbeat. Severe cases of dehydration can cause shock, seizures, kidney failure, unconsciousness and death. Usually, drinking enough fluids is enough to prevent dehydration, but if you are ill or exercising strenuously in hot weather, you can still experience dehydration.
One of the first symptoms of diabetes is often excessive thirst along with producing large amounts of urine. Other symptoms of diabetes include excessive hunger, fatigue, weight loss and vision changes. Sometimes these symptoms may come on very suddenly and with no warning, according to the World Health Organization. Left unchecked, diabetes can cause damage to the heart, eyes, kidneys and other body organs. Depending on the type of diabetes, your doctor might prescribe injected or oral medications along with lifestyle changes, such as quitting smoking and losing weight.
Organ Damage and Excessive Thirst
Heart failure prevents maintenance of adequate blood flow. The reduction in blood volume induces thirst. Kidney failure causes extreme thirst, because the kidneys can no longer maintain body fluid balance. Liver problems may cause blood vessels in the esophagus to become enlarged and bleed. The decrease in blood volume caused by bleeding, triggers extreme thirst due to body fluid imbalance. Polydipsia, a mental condition that causes extreme thirst, has many causes, including stress and anxiety. If you are thirsty for no apparent reason, speak with your doctor to rule out a medical or emotional problem.
- EurekAlert; Drink At Least 8 Glasses of Water a Dajy - Really?; August 8, 2002
- University of California, Berkeley: Fluid and Electrolyte Balance
- Medline Plus; Thirst-Excessive; Linda Vorvick, MD; January 31, 2011
- World Health Organization; Diabetes; January 2011
- Austin Community College: Fluid and Electrolyte Summary
- Ohio State University Wexner Medical Center: Common Characteristics of Liver Disease