Drinking Too Much Water: Causes and Symptoms

Drinking too much water can lead to a rare, severe condition called water toxicity, or water intoxication. Symptoms include confusion, nausea, and vomiting. If it’s untreated, water toxicity can cause seizures, coma, and even death.

Drinking enough water each day prevents dehydration, regulates body temperature, and lubricates and cushions your joints. It’s difficult for healthy adults to drink too much water. Psychiatric disorders or other conditions may cause water toxicity. Water-drinking competitions or forcing yourself to drink a lot of water in a short time can also cause it.

Drinking more water than your body needs mostly just results in increased urination. It’s rare, but drinking too much water too fast can potentially overwhelm your system. The fluid balance in your body can be thrown off if you consume too much water before your kidneys can filter out the excess.

This imbalance can cause the amount of water within your cells to increase. Increased pressure within the brain may cause a slower heart rate and high blood pressure. A lack of treatment or a delay in diagnosis may result in seizures, coma, and death.

It’s unlikely that you will consume too much water. Water toxicity is rare, but certain risk factors can increase your risk:

• High ADH levels and water loss: Illnesses like gastroenteritis, or the “stomach flu,” can cause you to drink a lot of water to replace fluids lost through diarrhea or vomiting. Your kidneys may hold onto too much water if you also have high levels of antidiuretic hormone (ADH). ADH makes your body retain water.
• Physical activity: You may develop water toxicity if you drink too much water after exercising without replenishing lost electrolytes. These minerals balance the amount of fluids in your body, manage the pH (acidity) of your blood, and assist in nerve and muscle function.
• Psychogenic polydipsia: This condition causes excessive thirst. It’s most common in people with bipolar disorder, depression, and schizophrenia.
• Unusual circumstances: Water-drinking competitions or forcing yourself to drink a lot of water in a short time can also cause intoxication.

Water toxicity may cause symptoms like:

• Altered mental status
• Confusion
• Disorientation
• Nausea or vomiting
• Seizures or coma (in severe cases)

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. Normal urination patterns may vary. Adults generally need to urinate five to six times per day.

Your urine will be a pale yellow color if you consume enough fluid. It may be a sign that you are drinking more than you need if your urine is colorless or you urinate too frequently.

Water Toxicity in Infants 

Breast milk or formula is generally enough fluid to hydrate infants aged 4-6 months old. Infants who take in too much water can be at risk for water toxicity, which may cause symptoms like:

• Brain damage due to encephalopathy (brain swelling)
• Cyanosis (blue tint to the skin)
• Puffy face
• Seizures

The right amount of water you need per day can vary. Adequate water intake for healthy people is based on age and sex. Adult women need about 11.5 cups of total fluid per day, and adult men need about 15.5 cups.

About 20% of your water needs are met through water-rich foods, like fruits and vegetables. This 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. Make sure to drink at least 2 cups before a workout. Continue to sip water or a sports drink during exercise, and replenish lost fluids afterward. Running a fever, having diarrhea, or vomiting can also cause fluid loss.

Water is essential for life. Drinking too much water is possible, but water toxicity is rare. Overconsumption of water is typically associated with health conditions, medications, or unusual circumstances. Talk to a healthcare provider about how to manage your fluid needs if you may be at risk for water toxicity or if you are not sure how much water you need a day.