Is it possible to drink too much water?

Hi Alice,

I drink eight to ten 8-ounce glasses of water a day. Is it ever possible to drink too much water? A friend told me that it was possible and that drinking too much water sets your bodily fluids out of balance. Please let me know the details about water intake and health. Thanks.

Dear Reader,

What a great question! Water plays a vital role in maintaining a variety of body processes, such as the transportation of nutrients, maintenance of body temperature, and helping the body's immune system to name a few. More than half of the human body is made up of water, and it continuously sends the brain signals to drink more water or excrete it in order to maintain homeostasis, or internal fluid balance. As a result, a dry mouth or a feeling of thirst indicates a need to replenish fluids, whereas a feeling of fullness from drinking enough liquids is one way the body says to stop drinking. While the kidneys are equipped to efficiently process fifteen liters of water a day, it's possible to consume too much water. However, exactly how much water someone needs in a day is dependent by their lifestyle. The recommendations for how much water a person needs vary greatly. While some sources cite four to six glasses a day, others say upwards of eleven. Those who take certain medications or live with certain health conditions may need to drink more or less, while athletes often need to consume more. 

There are a few conditions that can cause individuals to overconsume water, one of them being known as psychogenic polydipsia. This relatively rare, psychological condition causes people to experience abnormal thirst and can cause people to experience another condition known as hyponatremia. This condition occurs when the levels of sodium in the body are abnormally low or diluted by an excess of water. When there is an excess of water in the body, it flows into your cells and causes them to expand. While most of the body's cells can handle this swelling, the brain cells cannot, and this swelling can be potentially life-threatening. 

Individuals who partake in high-intensity, long-distance activities, such as marathons, can experience what is known as acute hyponatremia. This form of hyponatremia is considered to be potentially more high risk than non-acute, as its immediate onset usually means that there is more rapid brain swelling occurring. So, it's key to drink sports drinks along with water during any vigorous and prolonged athletic activity, as sports drinks contain sodium, among other electrolytes, to help keep everything in balance. Usually, the body can handle large fluctuations in water-sodium balance when you drink a lot of water, but if you have kidney problems, take a diuretic, have severe burns, or have stress due to surgery, you may be at higher risk for hyponatremia. If you are experiencing any of the symptoms associated with hyponatremia, such as nausea and vomiting, confusion, seizures, or a loss of consciousness, it's critical to seek medical attention immediately. 

In addition to drinking water, hydration can come from the foods that you choose to eat. Many fruits and vegetables have a high water content, and they contribute to how much water you consume per day. If you're unsure if you're getting enough hydration, one way to tell is by how thirsty you feel and the color of your urine. If you aren't often thirsty and your urine is a light yellow color, you're likely getting enough water. If you're not sure if you're getting enough water for you or may be drinking too much, it may be worth speaking with a health care provider who can speak to your specific health needs. 

Overall, water is a great beverage choice because it quenches your thirst and keeps the body hydrated. As long as you have a source of clean, fresh water — feel free to drink up!

Last updated May 20, 2022
Originally published Mar 26, 1999

Submit a new comment


This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

The answer you entered for the CAPTCHA was not correct.