Because diuretics rid the body of unnecessary retained fluids, physicians often prescribe them to treat heart failure, congestive heart failure, high blood pressure, edema and some types of kidney and liver diseases.You probably know that caffeinated beverages act as diuretics, meaning they cause increased passing of urine. This applies to caffeinated teas as well. There are also noncaffeinated herbal teas that cause the same effect. Consult with your doctor before drinking diuretic herbal teas if you're taking medications or intend to use herbal tea to treat a major illness.
In traditional medicine systems, green tea, with its naturally occurring caffeine content, was used as a stimulant and diuretic. Green tea leaves are processed to make black tea and oolong. However, unprocessed green tea may provide the greatest health benefits due to its high antioxidant content, which may be effective in preventing certain cancers. You may want to limit your green tea intake if you drink other caffeinated beverages because too much caffeine can cause harmful side effects in the short and long term. For people without medical issues, 200 to 300 milligrams of caffeine daily is generally considered harmless, according to MedlinePlus. One 6-ounce cup of green tea can contain between 16 and 41 milligrams of caffeine, depending on the brand and steep time, according to a study published in 2008 in the "Journal of Analytical Toxicology."
Dandelion Leaf Tea
Dandelion tea has been used in traditional Chinese and European systems of medicine to treat an array of ailments. While the roots and flowers have different purposes, the leaves of the dandelion have a diuretic effect. In a study published in the "Journal of Alternative and Complementary Medicine" in 2009, scientists gave volunteers dandelion leaf extract and measured their urine output volume and frequency of urination. All 17 volunteers had an increase in urination -- a 5 percent increase on average -- within five hours after taking the extract.
Horsetail, a nonflowering weed closely related to the fern, is an herb that has been used as medicine since the times of the Greeks and Romans. Although there have been few studies examining the effects of this herb on humans, horsetail has traditionally been used as a diuretic. It's sometimes recommended for the treatment of kidney stones, though its effectiveness has not been proven. It's also used to treat bladder stones, edema, urinary tract infections and incontinence, which is the inability to control urination. Horsetail tea may lead to thiamine deficiency if drunk regularly over a long period, according to MedlinePlus.
Stinging Nettle Tea
According to the University of Maryland Medical Center, stinging nettle has been used as a medicinal herb since the medieval period in Europe, where it was used as a diuretic. Stinging nettle is also called common nettle and garden nettle, and its scientific name is Urtica dioica. In a study published in the "Journal of Ethnopharmacology" in 2000, stinging nettle was found to rid the body not only of excess water but also excess sodium. The study found that taking more than 24 milligrams of stinging nettle per kilogram of body weight in one hour can be toxic for the body, but low doses are harmless.