How much water should you drink daily for healthy kidneys?

The kidneys filter approximately 50 gallons (about 189 liters) of blood daily, removing waste and excess fluids through urine. Staying hydrated helps dilute substances such as urea and sodium, lowering the risk of kidney stones, urinary tract infections, and long-term kidney damage, according to the Times of India.

Research from Australia and Canada, cited by Kidney Research UK, suggests that sufficient fluid intake may help the kidneys flush out waste more effectively and reduce the risk of developing chronic kidney disease. Water remains one of the most beneficial options for maintaining kidney health.

However, people with kidney disease, especially those undergoing dialysis, must monitor their fluid intake carefully, as their kidneys can no longer regulate fluids properly. The U.S. National Kidney Foundation warns that overhydration is also a risk. Though rare, drinking excessive amounts of water can dilute sodium in the blood and lead to hyponatremia, a potentially dangerous condition.

A person drinks water. Photo from Pexels

How much water do you need daily?

The commonly recommended "eight glasses a day" is a general suggestion rather than a universal rule. Actual water needs depend on age, activity level, climate, and individual health status.

According to the Mayo Clinic, total daily fluid intake, including water, beverages like tea and coffee, soups, and high-water-content foods such as fruit, should be around 3.7 liters (15.5 cups) for men and 2.7 liters for women.

Most doctors recommend 1.5 to 2 liters of plain water per day for healthy adults. Those living in hot climates or engaging in intense physical activity may require more, while people with end-stage renal disease may need less. Individuals prone to kidney stones are typically advised to produce at least 2.5 liters of urine daily, which usually requires drinking about 3 liters of water.

Are you drinking enough?

One way to assess hydration is by observing urine color, it should be pale yellow or nearly clear. Other signs of proper hydration include urinating six to eight times a day, not feeling thirsty, and avoiding fatigue or dizziness.

Do tea and coffee count?

Herbal teas, low-sugar juices, and even decaffeinated coffee contribute to daily hydration. Despite common belief, moderate amounts of caffeinated beverages like coffee and tea can also count toward total fluid intake, according to a 2016 study published in the American Journal of Clinical Nutrition.

Sugary soft drinks and energy drinks, however, are best avoided due to their high phosphate content, which can harm kidney function. Alcohol also dehydrates the body and does not contribute to daily fluid intake.