Dilutional Hyponatremia or Water Intoxication

A man drinking water close up
Too much water can be worse than too little -- water intoxication can be life threatening. Sara Hammarbaum, Freeimages

Dilutional hyponatremia, also known as water intoxication, is a potentially life-threatening condition which occurs when a person consumes too much water without an adequate intake of electrolytes. 

To put it simply, water in the body needs to contain enough salts and other ions, called electrolytes, to keep the body's cells functioning properly. If you take in too much water without enough electrolytes, the water can move into the cells of the body, causing them to swell.

The brain is particularly vulnerable to the effects of hyponatremia.

Who Is at Risk for Hyponatremia?

Most people are not at high risk for hyponatremia because the body is good at keeping fluid and electrolytes balanced. But some people are at higher risk: they might think they need more water than they do because they're in a compulsive state of mind as a result of drug use, or because they're encouraged to drink a lot of water without enough electrolytes.

Following are some groups who have been identified as "at higher risk" than others:

  • Users of stimulant drugs, especially when combined with dancing for hours on end.
  • People who've consumed drugs, including alcohol, and are trying to remove the drug from their bodies by drinking a lot of water.
  • People who are addicted to exercise, who work out for many hours a day and attempt to rehydrate themselves with water only.
  • People engaging in the promotion of behaviors related to anorexia nervosa in an attempt to lose excessive weight; drinking large amounts of water can be used in this way.
  • Newborn babies whose mothers avoid breastfeeding and feed them dilute formula and water, which can include the babies of drug-using mothers.
  • Endurance athletes
  • People with certain psychiatric conditions, such as schizophrenia, schizoaffective disorder, and bipolar disorder


In order to prevent water intoxication, it is important to address some of the factors that contribute to hypnotremia. Some things to watch for to help prevent hyponatremia include:

When Using Stimulants

People who use stimulants sweat out water and electrolytes quickly, due to the stimulant effects of the drug. This process speeds up when they're dancing for hours on end, which is common at raves and dance parties where people use drugs such as meth, cocaine, ecstasy (MDMA), bath salts, and lower doses of MXE or ketamine to keep them going.

It's important to drink water throughout the night, rather than all in one go — and also to consume enough salt to prevent water intoxication. This can be done by drinking rehydration fluid instead of water, eating salty foods when you drink water, or taking a small amount of salt with your water—about half a teaspoon per liter.

High doses of caffeine can also be used as a stimulant; energy drinks, for example, may contain large doses of caffeine and no electrolytes. In contrast, some sports drinks are designed for the proper hydration of athletes and contain the correct proportions of water and electrolytes, so they can be safer to consume for rehydration.

Some drinks may contain high amounts of caffeine, however, so caution is advised.

When Consuming Alcohol

People drinking alcohol can become dehydrated and attempt to hydrate themselves by drinking large amounts of water at the end of the night. But because the symptoms of water intoxication are similar to those of alcohol intoxication, the problem may be overlooked. The best way to avoid this is to alternate between alcoholic and non-alcoholic beverages and to include fruit juice and mixers, which contain salt.

When Losing Weight

People attempting to lose weight by exercising frequently should rehydrate themselves using water or drinks containing electrolytes. As with stimulant users, "little and often" is better than a lot of fluid all at once. And because stimulant users, over-exercisers, and people engaging in behaviors related to anorexia nervose are prone to compulsive behaviors, take extra care not to drink water compulsively.

Fruit juice may not be a good choice due to the high sugar content. Fruit juice tends to contain too many carbohydrates and too little sodium and may lead to stomach upset. People should also use caution when consuming sports drinks because they are often high in sugar and sodium.

When Feeding a Newborn

Parents of newborns should always follow the instructions for mixing formula exactly. Breast milk contains the right balance of electrolytes and water, but formula needs to be mixed as directed on the package instructions. Don't ever be tempted to water down formula as a way to save money. Babies are especially vulnerable to hyponatremia.

If you think you or someone else may have water intoxication, call 911 or take them to an emergency room at once. Fast treatment could save their life.

3 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Elizabeth Hartney, BSc, MSc, MA, PhD
Elizabeth Hartney, BSc, MSc, MA, PhD is a psychologist, professor, and Director of the Centre for Health Leadership and Research at Royal Roads University, Canada.