Diuretic drinks are drinks containing diuretics, which stimulate the formation of urine in the kidneys, thus causing increased urination. Some examples of diuretic drinks are coffee, tea and alcoholic drinks. Caffeine is a substance known to cause a mild diuretic effect, but it doesn't pose a significant risk of dehydration.
Diuretics are often referred to as water pills because they promote the loss of water by the body. In the process, sodium, potassium and chloride may also be excreted with the urine. Some patients, like those with hypertension, need to limit their intake of fluid and salt, and they take diuretics to control their levels of water and salt and prevent further illness.