Water Intoxication

What is water intoxication?

Water intoxication is when you have more water in your body than you need. It can cause a chemical imbalance that your body can’t clear out naturally by sweating or urinating (peeing).

Drinking too much water dilutes your blood and decreases the electrolytes in your body, especially sodium (hyponatremia). As a result, water moves into your body’s cells and causes them to swell. When you get too much water in your brain cells, it increases pressure on your brain and affects how it works. This leads to changes in your awareness, movement and behavior (altered mental status). Water intoxication is also potentially fatal.

It’s important to drink water as soon as you can if you feel thirsty, especially while exercising or during warm weather. If you have normal kidney function, it’s difficult to drink yourself into water intoxication. But it’s a good idea to be aware of how much water you drink if you have advanced kidney disease, or you’re an athlete who drinks a lot of water and you’re dehydrated. Let your thirst guide you. Don’t force yourself to drink more water after you quench your thirst.

Other names for water intoxication include:

• Water poisoning.
• Water toxicity.
• Hyperhydration.
• Overhydration.
• Water toxemia.
• Dilutional hyponatremia.
• Water-electrolyte imbalance.

Can drinking too much water kill you?

Yes, drinking too much water can be fatal.

What are the symptoms of water intoxication?

Water intoxication symptoms may include:

• Nausea and vomiting.
• Bloated stomach.
• Headache.
• Drowsiness.
• Muscle weakness.
• Muscle pain.
• Muscle cramps.
• Changes to your mental status, including confusion, irritability and dizziness.
• Swelling (edema) in your hands, feet and belly.

How do I know if I drank too much water?

It isn’t easy to know if you drank too much water. But the color of your pee can tell you a lot about your health. If you’re properly hydrated, your pee will be light yellow, like the color of light straw or lemonade. You may be drinking too much water if your pee is colorless or clear.

Stop drinking water if your pee is colorless and you have water intoxication symptoms.

What causes water intoxication?

Water intoxication can occur if you drink too much water. This is more likely to happen if you:

• Participate in endurance sports or exercise. Sports or exercises that cause you to sweat a lot over a long period, such as long-distance running, hiking or bicycling, can increase your chances of water intoxication as you drink a lot of water to avoid dehydration.
• Work in extreme heat. This includes working outside during hot weather or in hot buildings, such as a foundry.
• Have psychogenic polydipsia. This is a mental health condition that’s common in people who have schizophrenia. It compels you to drink more water than your body needs.
• Use MDMA (ecstasy or Molly) recreationally. MDMA acts as a hallucinogen and a stimulant. It may fill you with a lot of energy, which can cause you to overexert yourself, sweat a lot and drink lots of water to replenish lost fluids.
• Have a low body mass. Children under a year old can easily get too much water because they don’t need a lot due to their small size. They get all the water they need from breast milk (chest milk) or formula. But if you feel like your child needs water, they shouldn’t have more than 3 ounces. During baby swim classes, you should also be careful to ensure your child doesn’t accidentally ingest water.
• Use certain medications. Some antidepressants and antipsychotic medications may cause extreme thirst.

You can also get water intoxication if you have certain conditions that may make it hard for your kidneys to pee out extra water. These conditions may include:

• Chronic kidney disease.
• Liver disease.
• Congestive heart failure.
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Nonsteroidal anti-inflammatory drugs (NSAIDs) can also cause your kidneys to retain water.

How much water causes overhydration?

The amount of water that causes overhydration varies. It’s important to understand how your body uses water to know how much is too much for you. Your body removes excess water through your pee. In a day, this equals about 32 to 64 ounces (about 1 to 2 liters). In some people, water intoxication symptoms can develop after drinking about a gallon (3 to 4 liters) of water over an hour or two.

You can help prevent overhydration by:

• Drinking when you’re thirsty.
• Listening to your body.
• Stopping after you’ve quenched your thirst; don’t force yourself to drink.

What are the complications of water intoxication?

Without treatment, severe water intoxication symptoms may progress to:

• Seizure.
• Delirium.
• Coma.
• Death.

How is water intoxication diagnosed?

To diagnose water intoxication, a healthcare provider will first:

• Review your medical history.
• Ask about your symptoms.
• Perform a physical exam, including looking for signs of swelling in your hands, feet and belly.

They may also order blood tests and pee tests (urinalyses) to check your electrolyte levels.

How is water intoxication treated?

Water intoxication treatment usually includes:

• Stopping or restricting your water consumption.
• Treating the cause of water intoxication, which may include stopping certain medications.

Depending on the cause of water intoxication, you may need diuretics or IV fluids (intravenous, or through your vein).

How soon after treatment will I feel better?

In most cases, you should start to feel better within a few hours after you stop drinking water.

Can water intoxication be prevented?

You can’t prevent all causes of water intoxication, especially some that cause your kidneys to retain water. Talk to a healthcare provider if you have concerns about your risks.

But in general, pay attention to your body:

• Drink water when you’re thirsty. But avoid drinking large volumes of water over a short period — more than 32 ounces (about a liter) of water per hour is probably too much.
• Pay attention to the color of your pee. Your pee should look light yellow. Clear or colorless pee may indicate you have too much water in your body.
• Stop drinking if you feel nauseous, bloated or have a headache. These are early signs that you drank too much water.

Drinking sports drinks (electrolyte drinks), 100% fruit juice or coconut water in moderation can also help prevent water intoxication, especially if you’re sweating a lot. They help replenish your water and sodium levels.

What can I expect if I have water intoxication?

With proper treatment, the outlook for water intoxication is good. In mild cases, you should start to feel better within a few hours. In severe cases, it may take a few days before you recover.

Water intoxication death is rare.

When should I see a healthcare provider?

See a healthcare provider as soon as you or someone you know has signs of water intoxication. You’re less likely to have severe complications the faster you get treatment.

What questions should I ask a healthcare provider?

You may want to ask your provider:

• How will you diagnose water intoxication?
• How severe is my water intoxication?
• Can I get water intoxication from drinks other than water?
• How can I prevent water intoxication in the future?
• Should I drink sports drinks? How much and how often?

How much water can you drink a day?

Your body is unique, and the amount of water you need each day may be different from others’ needs. But on average, healthcare providers recommend the following daily fluid intake for adults:

• 125 ounces (3.7 liters) for people assigned male at birth (AMAB).
• 91 ounces (2.7 liters) for people assigned female at birth (AFAB).

Drinking more than the average amount is OK if you exercise a lot or live in a warm climate or at a higher elevation. But talk to a provider if you have concerns about how much water you should drink. They can tell you what’s appropriate.