Is There Such A Thing As Drinking Too Much Water?

Drinking enough water each day is important to prevent dehydration, help regulate body temperature, and lubricate and cushion your joints. However, drinking too much water can lead to a serious condition called water toxicity or water intoxication, but this is rare.

For healthy adults, it’s difficult to drink too much water. However, water toxicity may be caused by psychiatric and/or neurodevelopmental disorders, other medical conditions, the use of drugs like MDMA (ecstasy or molly), or unusual circumstances like water drinking competitions or forcing yourself to drink a large amount of water in a short period of time.

Water toxicity can also occur when someone loses sweat from exercise and then drinks plain water without adding replenishing electrolytes. This can lead to a serious and potentially fatal condition called hyponatremia, in which the amount of sodium in the blood is too low. Symptoms of hyponatremia may include nausea and vomiting, fatigue, headache, muscle cramps, altered mental state, agitation, seizures, and coma. 

What Happens When You Drink Too Much Water?

For a healthy adult, drinking more water than your body needs mostly just results in increased urination. However, while rare, drinking too much water too fast can potentially overwhelm your system. If you consume too much water before your kidneys can filter out the excess, the fluid balance in your body can be thrown off. This can cause the amount of water within your cells to increase.

Within the central nervous system, swollen neurons can trigger symptoms of confusion, headache, and drowsiness. In addition, increased pressure within the brain may cause a slower than normal heart rate and high blood pressure. And a lack of treatment or a delay in diagnosis may result in seizures, coma, and death.

Signs You're Drinking Too Much Water

No upper limit for water has been established because, in healthy people, the kidneys are able to excrete approximately 0.7 liters of fluid per hour to maintain proper fluid balance. However, to avoid water toxicity, experts advise never drinking more than 48 ounces (1.5 quarts or six cups) per hour.

The two simplest ways to assess your hydration status are to check the color of your urine and pay attention to how often you urinate. While normal patterns of urination may vary, adults generally need to urinate five to six times per day and no more than once after going to bed.

As for color, if you consume enough fluid your urine will be a pale yellow color. If your urine is colorless or you urinate too frequently, it may be a sign that you’re drinking more than you need.

Due to thirst regulation and comfort (a desire to prevent a too full bladder and too frequent urination) most people will not voluntarily overconsume water. But as noted, fluid balance can be thrown off due to factors like medical conditions, medications, or a forced excessive consumption.

How Much Water Should You Drink in a Day?

A 2023 National Institutes of Health study concluded that adults who stay well-hydrated appear to be healthier, develop fewer chronic conditions, such as heart and lung disease, and live longer compared to those who may not consume enough fluids.

The right amount of water you should consume per day can vary, but in general, adequate water intake for healthy people are based on age and sex. As a baseline, adult women need about 11.5 cups of total fluid per day and adult men need about 15.5 cups.

However, about 20% of your water needs are met through water-rich foods, like fruits and vegetables. That leaves about 9 cups of water per day for women and about 13 cups for men. It’s best to space out your water intake throughout the day to replace fluid as you lose it and prevent dehydration.

Prolonged exercise or hot and humid weather can further increase water needs, as can running a fever, having diarrhea, or vomiting.

As a general rule of thumb, people who exercise should:

• Drink about 16 ounces (2 cups) of water two hours before a workout.
• Continue to sip water during exercise. Aim about one half to one cup of fluid every 15 to 20 minutes. Switch to a sports drink rather than plain water after the first hour to replace both fluid and electrolytes.
• Drink even when you no longer feel thirsty.
• Within six hours of finishing a workout drink 16 to 24 ounces or 3 cups of fluid for every pound you lost while exercising.
  

A Quick Review

Water is a vital nutrient and while drinking too much water is possible, water toxicity is rare. Overconsumption of water is typically associated with medical conditions, medications, or unusual circumstances.

If you feel you may be at risk for water toxicity or you’re not sure how much water you need daily, talk to your healthcare provider about how to manage your personal fluid needs.