Health Topic

Fluid and Electrolyte Balance

How do you know if your fluids and electrolytes are in balance? Find out.

Reviewed Reviewed by a registered pharmacistGeneral information

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Fluid and Electrolyte Balance

Electrolytes are minerals that have an electric charge when they are dissolved in water or body fluids, including blood. The electric charge can be positive or negative. You have electrolytes in your blood, urine (pee), tissues, and other body fluids.

Electrolytes are important because they help:

  • Balance the amount of water in your body
  • Balance your body's acid/base (pH) level
  • Move nutrients into your cells
  • Move wastes out of your cells
  • Support your muscle and nerve function
  • Keep your heart rate and rhythm steady
  • Keep your blood pressure stable
  • Keep your bones and teeth healthy

The main electrolytes in your body include:

  • Bicarbonate, which helps maintain the body's acid and base balance (pH). It also plays an important role in moving carbon dioxide through the bloodstream.
  • Calcium, which helps make and keep bones and teeth strong.
  • Chloride, which also helps control the amount of fluid in the body. In addition, it helps maintain healthy blood volume and blood pressure.
  • Magnesium, which helps your muscles, nerves, and heart work properly. It also helps control blood pressure and blood glucose (blood sugar).
  • Phosphate, which works together with calcium to build strong bones and teeth.
  • Potassium, which helps your cells, heart, and muscles work properly.
  • Sodium, which helps control the amount of fluid in the body. It also helps your nerves and muscles work properly.

You get these electrolytes from the foods you eat and the fluids you drink.

An electrolyte imbalance means that the level of one or more electrolytes in your body is too low or too high. It can happen when the amount of water in your body changes. The amount of water that you take in should equal the amount you lose. If something upsets this balance, you may have too little water (dehydration) or too much water (overhydration). Some of the more common reasons why you might have an imbalance of the water in your body include:

  • Certain medicines
  • Severe vomiting and/or diarrhea
  • Heavy sweating
  • Heart, liver or kidney problems
  • Not drinking enough fluids, especially when doing intense exercise or when the weather is very hot
  • Drinking too much water

The names of the different types of electrolyte imbalances are:

A test called an electrolyte panel can check the levels of your body's main electrolytes. A related test, the anion gap blood test, checks whether your electrolytes are out of balance or if your blood is too acidic or not acidic enough.

The treatment for an electrolyte imbalance depends on which electrolytes are out of balance, if there is too little or too many, and what is causing the imbalance. In minor cases, you may just need to make some changes to your diet. In other cases, you may need other treatments. For example:

  • If you don't have enough of an electrolyte, you may get electrolyte replacement therapy. This involves giving you more of that electrolyte. It could be a medicine or supplement that you swallow or drink, or it may be given intravenously (by IV).
  • If you have too much of an electrolyte, your provider may give you medicines or fluids (by mouth or by IV) to help remove that electrolyte from your body. In severe cases, you may need dialysis to filter out the electrolyte.

It sits within Food and Nutrition.

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Research on Fluid and Electrolyte Balance

29 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Diagnosis and Tests

Related Issues

Genetics

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Water-Electrolyte Balance, Water-Electrolyte Imbalance. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Fluid and Electrolyte Balance, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.