Electrolytes

What are electrolytes?

Electrolytes are substances that have a natural positive or negative electrical charge when dissolved in water. An adult's body is about 60% water, which means nearly every fluid and cell in your body contains electrolytes. They help your body regulate chemical reactions, maintain the balance between fluids inside and outside your cells, and more.

Your body gets electrolytes or their components from what you eat and drink. Your kidneys filter excess electrolytes out of your body and into your urine. You also lose electrolytes when you sweat.

Key terms to know:

• Hyper-: A condition that starts with “hyper” means it involves too much of something.
• Hypo-: A condition that starts with “hypo” means it involves too little of something.
• Ion: An atom that has an electrical charge.
• Cations: Ions with a positive charge.
• Anions: Ions with a negative charge.
• pH: A scale that measures whether a liquid is an acid or base. Your body’s natural blood pH is between 7.36 and 7.44.
• Acidic: Has a pH of less than 7.
• Neutral: Has a pH of 7.
• Basic: Has a pH of more than 7 (basic is also known as “alkaline”).

What do electrolytes do?

Your cells use electrolytes to conduct electrical charges, which is how your muscles contract. Those same electrical charges also help with chemical reactions, especially when it comes to hydration and the balance of fluids inside and outside of cells.

The key principle that electrolytes rely on is that certain chemical elements can naturally hold a positive or a negative electrical charge. When those elements are dissolved in a liquid, that liquid can then conduct electricity.

An example of this is salt water, which conducts electricity easily. Salt consists of sodium (positively charged) and chlorine (negatively charged), and when combined, their charges balance each other out. Atoms with an electrical charge are called ions (positive ions are called cations, while negative ions are called anions).

Dissolving salt in water splits the sodium and chlorine atoms apart, which means they go back to being positively and negatively charged. Electricity jumps between the sodium and chlorine ions — not the water molecules — because they have opposite electrical charges.

At the most basic chemical level, electrolytes help your body maintain balance. Just like electricity uses ions to travel from place to place in salt water, your body uses ions to transport chemical compounds in and out of cells.

What are the key electrolyte components?

There are several key elements that your body needs to maintain normal electrolyte levels. The following section includes the major elements, marked as positive (+) or negative (-), and what happens when there’s too much or too little of that element.

Sodium (+)

Sodium plays a critical role in helping your cells maintain the right balance of fluid. It’s also used to help cells absorb nutrients. It’s the most abundant electrolyte ion found in the body.

• Hypernatremia (too much sodium): Can cause confusion or behavior changes, unusually strong reflexes and loss of muscle control, seizures and coma.
• Hyponatremia (not enough sodium): Confusion, irritability, weakened reflexes, nausea and vomiting, seizures and coma.

Magnesium (+)

Magnesium helps your cells as they turn nutrients into energy. Your brain and muscles rely heavily on magnesium to do their job.

• Hypermagnesemia (too much magnesium): Heart rhythm changes and arrhythmias, weakened reflexes, decreased ability to breathe and cardiac arrest (your heart stops).
• Hypomagnesemia (not enough magnesium): Muscle weakness, twitching and loss of control, heart arrhythmias. This commonly happens in connection with calcium and potassium deficiencies.

Potassium (+)

Your cells use potassium alongside sodium. When a sodium ion enters a cell, a potassium ion leaves, and vice versa. Potassium is also especially critical to your heart function. Too much or too little can cause serious heart problems.

• Hyperkalemia (too much potassium): Weakness, inability to move muscles, confusion, irregular heart rhythms (arrhythmias).
• Hypokalemia (not enough potassium): Muscle weakness and cramps, feeling unusually thirsty and needing to pee frequently, dizziness or passing out when standing up too quickly. At higher levels, muscle tissue begins to break down (a condition called rhabdomyolysis, which can severely damage your kidneys) and heart arrhythmias become a serious threat.

Calcium (+)

Calcium is a key element in your body, but it does more than just build strong bones and teeth. It’s also used to control your muscles, transmit signals in your nerves, manage your heart rhythm and more. Having too much or too little calcium in your blood can cause a wide range of symptoms across different systems in your body.

Hypercalcemia (too much calcium)

• Brain: Headache, fatigue, apathy and confusion.
• Digestive tract: Constipation, abdominal pain and vomiting.
• Kidneys: Frequent need to pee, kidney stones and kidney failure.
• Heart: Arrhythmias, some of which can be severe.
• Skeletal: Pain in the bones and joints.

Hypocalcemia (not enough calcium)

• Brain: Confusion and behavior changes.
• Muscles: Unusually strong reflexes and loss of muscle control, muscle twitching, spasms in the throat muscles making it hard to speak or breathe.

Chloride (-)

Chloride (the name for a chlorine ion) is the second-most abundant ion in the body. It’s also a key part of how your cells maintain their internal and external balance of fluid. It also plays a role in maintaining the body’s natural pH balance.

Hyperchloremia (too much chloride)

This can cause acidosis, which is when your blood’s acidity is too high. It results in nausea, vomiting and fatigue, as well as rapid, deeper breathing and confusion. This usually happens in connection with too much or too little potassium.

• When related to hyperkalemia: When associated with too much potassium, it can cause severe kidney problems or kidney failure.
• When related to hypokalemia: When connected with too little potassium, it can cause diarrhea, fluid leakage from the pancreas, and other serious urinary tract problems.

Hypochloremia (not enough chloride)

• This causes your blood to become more alkaline, a condition called alkalosis. It usually happens with hyponatremia or vomiting. Symptoms of alkalosis are apathy, confusion, arrhythmias and muscle twitching or loss of control.

Phosphate (-)

Phosphate is a phosphorous-based molecule that’s a key part of transporting chemical compounds and molecules outside your cells. It helps your cells metabolize nutrients, and it’s also a key part of molecules called nucleotides, which are the building blocks that make up your DNA.

• Hyperphosphatemia (too much phosphate): This typically causes you to experience hypocalcemia because your body tries to use calcium as a substitute for phosphorus. It usually doesn’t cause symptoms until it becomes severe, and symptoms of hypocalcemia also often happen with this. It can also be associated with excessive itching.
• Hypophosphatemia (not enough phosphate): The early symptom of this condition is usually muscle weakness. As it gets worse, more severe symptoms occur. They include rhabdomyolysis (breakdown of muscle tissue, which can cause severe kidney damage), seizures, reduced heart function and trouble breathing (caused by muscle weakness).

Bicarbonate (-)

Not all the carbon dioxide that your body makes gets sent to your lungs for you to breathe it out. Instead, some gets recycled into bicarbonate, which your body uses to keep your blood pH levels normal.

• Acidosis. Too little bicarbonate causes acidosis, where your blood is too acidic. This causes fatigue, nausea and vomiting, and you will breathe faster and deeper. It can also cause confusion.
• Alkalosis. Too much bicarbonate causes alkalosis, where your blood becomes too alkaline. Symptoms include confusion, apathy, arrhythmias and muscle twitching.

What tests help identify electrolyte problems?

Electrolyte problems are detectable using several different varieties of lab tests. Testing usually involves a broader type of test called a metabolic panel. If those results are abnormal, your healthcare provider may order follow-up tests, which can narrow down what’s causing the electrolyte imbalances. These follow-up tests are critical, as the specific cause of an electrolyte imbalance may need a specific type of treatment that won’t work for other causes.

Broader tests that can detect electrolyte problems include the following blood tests:

Basic metabolic panel

This test looks at several different processes in your body and shows data related to:

• BUN (blood urea nitrogen). This is a test that shows how well your kidneys are functioning and may suggest dehydration.
• The balance of fluids and several electrolytes, including sodium, potassium, carbon dioxide and chloride levels.
• Blood sugar. This test may indicate diabetes or prediabetes if you are fasting.

Comprehensive metabolic panel

This test is similar to the basic metabolic panel but with additional data gathered. The additional items gathered include:

• Calcium levels.
• Albumin (a protein produced by your liver) levels.
• Total blood protein levels.
• Bilirubin (a chemical compound made in your liver).
• Levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), enzymes that are connected to your liver function.

Electrolyte panel

This is a broader test like the above metabolic panels, but it only looks for electrolytes. The electrolytes analyzed include sodium, chloride, potassium and bicarbonate.

Tests that are more specific for electrolyte problems include:

• Aldosterone blood test. This test looks for a specific hormone produced by your kidneys. The results can indicate certain types of electrolyte problems.
• Aldosterone 24-hour urine test. This test also looks for aldosterone but does so using several urine samples collected during a 24-hour timeframe.
• Anion gap blood test. The test compares the levels of specific electrolytes to see if there’s a difference between the measured levels of positive-charge and negative-charge electrolytes, which may be is a sign of certain conditions.
• Antidiuretic hormone test (blood). This test looks for levels of antidiuretic hormone. It can help rule out certain medical conditions that share symptoms — especially excessive thirst or fluid imbalance — with electrolyte-based conditions.
• Carbon dioxide blood test. This test measures the amount of carbon dioxide in your blood. That level can indicate if your blood is too acidic or too alkaline (basic).
• Chloride blood test. This test analyzes a blood sample for the level of chloride found in your blood.
• Chloride urine test. This test measures the amount of chloride in a urine sample. In some cases, it can involve several samples taken over a 24-hour period.
• Magnesium blood test. This test analyzes levels of magnesium in your blood.
• Blood osmolality test. This test measures the amount of certain substances in your body. It’s frequently used in cases where you’re dehydrated, overhydrated, or when poisoning is possible or suspected.
• Urine osmolality test. This test checks fluid balance, especially with changes in how often you need to pee. Urine osmolality tests use a “clean-catch” method, which requires getting the sample in a way so that there’s no contamination from microbes that may be on your genitals.
• Phosphorus blood test. This test measures the amount of phosphorus in your blood.
• Phosphorus urine test. This test measures the amount of phosphorus that’s found in your urine. It may involve more than one sample taken over a 24-hour period.
• Sodium blood test. This test measures the level of sodium in your blood.
• Sodium urine test. This test measures the amount of sodium in your pee. It can involve multiple samples collected over a period of 24 hours.
• Urine concentration test. This test shows healthcare providers how well your kidneys are functioning, especially their ability to manage the amount of fluid in your body. It looks specifically for the concentration of particles in your urine, electrolyte levels and particle concentration (osmolality).

What type of results will I get?

Most lab results include your result number and a reference range. A reference range has an upper and a lower limit, and any result that falls between the two is considered a “normal” result. Most of these results are communicated as "how much of a substance can be found in a specific sample size."

Mass is a unit of “how much.” It’s not the same as weight. The units of mass that are used are millimoles, milliequivalents or milligrams.

• Millimoles are the most constant and can be used for all electrolyte atoms and molecules.
• Milliequivalents per liter are often used instead of millimoles. This is because milliequivalents take into account the strength of an ion's charge, which is why ions with stronger charges have different amounts than the same test results in millimoles.
• Milligrams per deciliter may sometimes be used for larger atoms and molecules.

The prefix “milli-" means “1/1,000th.” The units of volume are usually displayed as a liter or fractions of a liter, like a deciliter (dL, which is 1/10th of a liter) or milliliter (mL, which is 1/1,000th of a liter).

What are the normal ranges for electrolyte levels?

This infographic lists the normal (typical) ranges for each electrolyte in your blood.

This infographic lists the normal (typical) ranges for each electrolyte in your urine.

Does a normal result mean everything is fine, or does an abnormal result always mean I have a problem?

Because everyone is different, sometimes you may have a result that falls outside the reference range. In other cases, you may have a normal result, but symptoms you're having and other test results will show you have a health problem.

One way to understand it is to think of the carnival trick where an entertainer spins a plate on the end of a wooden stick. If the plate leans too far in any direction, it will fall off, so balance is crucial. Your electrolyte levels and lab results rely on a similar balancing act, and your body is always trying to keep things as balanced as possible. Your body may be masking a problem by compensating with another body system or process. If your medical provider runs more than one test, they are likely making sure that your body isn’t hiding one problem by creating another.

When should I know the results of the test?

Your healthcare provider or their staff can tell you when to expect your test results back.

When should I call my doctor?

If you don't understand your test results or have a result that isn't within the reference range and you have questions or concerns, you should call your healthcare provider. You should also call your healthcare provider if you notice a sudden change in any symptoms related to any test done on your electrolyte levels.

A note from Cleveland Clinic
Electrolytes are an essential part of how your body functions, affecting everything from hydration to how your heart beats. They can also help doctors diagnose a wide range of medical conditions and problems. Understanding electrolytes and the potential concerns that surround them can help you care for yourself, and help you avoid future health concerns. That way, you can take charge of your electrolytes and keep them from negatively affecting your life and routine.