What blood tests can tell you about electrolytes and why they matter

These minerals are essential for the proper functioning of almost every body part, and imbalances can indicate a metabolic issue. Will you benefit from supplementation?

WRITTEN BY

Jennifer Chesak

REVIEWED BY

Dominic D'Agostino, PhD

Updated: 07/30/2025|14 min read

Electrolytes help maintain fluid balance and enable numerous bodily functions, including blood pressure regulation, nerve signaling, and muscle contraction. Although electrolytes are often discussed in the context of sports, maintaining electrolyte balance is crucial for everyone.

You can think of electrolytes as powering the body’s “electrical system.” In fact, the word “electrolyte” originates from the Greek word “ēlektro-,” which means “amber.” Amber, when rubbed, produces a static charge, which can attract other objects, a phenomenon later associated with electricity. Electrolytes carry either a positive or negative charge, which allows them to interact with each other to help the brain and body communicate.

If certain electrolyte levels rise too high or fall too low, they can disrupt everything from heart rhythm to neurological function. Electrolyte imbalances are associated with metabolic syndrome (MetS), cardiovascular issues like hypertension, heart failure, and arrhythmias, and neurological conditions such as seizures, migraine with aura, and movement disorders.

Most people can meet their electrolyte needs through proper nutrition and hydration. However, you may need supplementation if you have certain medical conditions, take some medications, are very active, or are exposed to an extremely hot environment for an extended period.

To understand your electrolyte status, get your electrolyte levels tested. A basic metabolic panel generally includes an electrolyte panel, which can reveal your current levels and identify any imbalances before they develop into health problems. Your clinician can help you interpret the results and determine if a supplement or dietary changes would be beneficial, or whether you need treatment for an underlying condition.

Here’s what you need to know about electrolytes, what test results mean, and when supplementation may be helpful.

This information does not constitute medical advice. Talk to your doctor for specific questions about your personal lab results.

Why do electrolyte levels matter for health?

Electrolytes are minerals and other compounds that maintain the body’s fluid balance, facilitate nerve signaling and muscle contraction, regulate the cardiovascular system, and more. They include sodium, potassium, chloride, magnesium, calcium, phosphate, and bicarbonate. An electrolyte imbalance means the body has either an overconcentration or a dilution of electrolytes, which can lead to issues with various systems.

Many factors can affect your levels in the short term, including your hydration status, hormone levels, nutrient intake, and recent extreme physical activity. For this reason, a single result that is slightly out of the normal range may not be cause for concern.

Some acute electrolyte imbalances, however, can lead to medical emergencies. For example, low sodium or potassium can cause rhabdomyolysis, where skeletal muscle breaks down and leaks into extracellular fluid and the bloodstream. This rare condition sometimes occurs after traumatic injury, very intense or prolonged exercise, or in people with physically demanding jobs or who work in the heat, like the military or firefighters.

There isn’t good data on the prevalence of short-term or chronic electrolyte disorders in the general population, as most studies have investigated hospitalized or elderly community-dwelling patients. However, some people tend to be at greater risk for an electrolyte imbalance, including those with Type 2 diabetes or cardiovascular disease, older adults, and athletes.

Maintaining fluid balance

Electrolytes help maintain fluid balance via osmotic concentration gradients. Different areas of your body require specific fluid amounts: in the bloodstream, between the brain and the skull, in each cell (i.e., intracellular fluid), and between cells (i.e., interstitial fluid). Through osmosis, your body uses electrolytes to pull water from areas of high concentration to areas with lower concentration, so every cell has the proper amount of fluids.

Facilitating nerve signaling and muscle contraction

Another key mechanism involving electrolytes is the sodium-potassium pump, a protein in cell membranes. Using adenosine triphosphate (ATP, your body’s universal energy currency), the sodium-potassium pump moves ions against their concentration gradients: It dispenses three sodium ions from the cell and brings in two potassium ions to create a net positive charge outside the cell and a negative charge inside, leading to the cell’s resting membrane potential. The resting membrane potential allows cells to generate an action potential, a change in voltage across cell membranes that generates the electrical signals needed for neuronal communication and muscle contraction.

Regulates cardiovascular health

The sodium-potassium pump also regulates intracellular sodium levels, influencing the activity of the sodium-calcium exchanger, the release of one calcium ion from the cell in exchange for bringing in three sodium ions. Proper calcium concentration management aids heart muscle contraction. Additionally, the sodium-potassium pump supports the kidneys by managing the reabsorption of essential substances and filtering out waste. And it influences blood pressure through vascular and smooth muscle control, which regulates blood vessel constriction and dilation.

The connections between electrolyte balance and metabolic health

A metabolic condition may affect your electrolyte levels and how they function—and an ongoing electrolyte imbalance may affect your metabolic health.

For example, research reveals links between electrolyte imbalances and metabolic syndrome (MetS), a cluster of metabolic health risk factors that increases the risk of cardiovascular disease, stroke, Type 2 diabetes, and is associated with the risk of dementia, cancers, and other health conditions. In a 2020 study of 256 people with MetS, more than 40 percent had an electrolyte disorder. But it’s unclear if electrolyte issues lead to metabolic concerns, or vice versa.

One factor may be mitochondrial dysfunction. ATP powers the sodium-potassium pump and is generated in your mitochondria, a.k.a., the powerhouses of cells. High blood glucose levels increase the production of reactive oxygen species, elevating oxidative stress, which damages mitochondria and makes them less efficient, leading to insulin resistance. When mitochondria work less efficiently because of worsened metabolic health, ATP production becomes impaired, disrupting the function of the sodium-potassium pump.

At the same time, sodium-potassium pump issues from electrolyte imbalances may contribute to worsened metabolic health by disrupting fluid balance, acid-base balance, and other metabolic processes. For example, high sodium causes water retention, which can cause high blood pressure, one of a cluster of conditions that define MetS.

Additional research links deficiencies in the electrolyte magnesium with obesity and the risk of developing MetS and Type 2 diabetes. Although researchers are trying to understand the exact mechanisms, they could include nutritional deficiencies, calcium imbalance, and kidney issues. So, connections between electrolyte imbalances and metabolic health issues are likely multifactorial.

What to know about the electrolytes in a blood panel

You may get electrolyte testing as part of a basic metabolic panel, or you might monitor your electrolytes regularly because of underlying conditions, including cardiovascular disease, kidney disease, liver disease, migraine, autoimmune disorders, and cystic fibrosis.

You can get your electrolytes tested through your doctor, an independent lab, or through Levels. Regardless of how you get your labs, electrolyte test results should be analyzed in relation to each other and in the context of other labs and factors unique to you. Since several factors can affect an electrolyte test—including your hydration status, recent physical activity or heat exposure, and diet—follow the lab’s or your doctor’s recommendations about what to avoid before undergoing an electrolyte test.

Here’s a detailed look at each electrolyte and its relation to health.

Sodium

What it is: Sodium is a mineral we get from our diet. It’s a component of salt, comprised of 40 percent sodium and 60 percent chloride. About 12 percent of dietary sodium intake comes from consuming foods that naturally contain it. Salt sprinkled on your food during cooking or at the table accounts for about 11 percent, and commercially processed foods account for about 77 percent. Sodium is often associated with hypertension—particularly table salt, but less so other kinds of sodium.

How it works: Sodium, along with potassium, maintains extracellular fluid volume and facilitates nerve signaling, muscle contraction, and blood pressure control via the sodium-potassium pump.

Normal range: 135 to 145 millimoles per liter (mmol/L)

Related conditions:

• Hyponatremia (low sodium) can cause confusion, seizures, and coma. If left untreated, it can also progress to rhabdomyolysis.
• Hypernatremia (high sodium) means your body has too much sodium in the bloodstream. This can lead to thirst and cause muscle twitching, confusion, seizures, and coma.

Potassium

What it is: Potassium is another mineral we glean from diet, especially from avocados, bananas, oranges, potatoes, spinach, broccoli, squash, beet greens, and certain beans and legumes. It’s vital for proper heart, nerve, and skeletal muscle function.

How it works: Along with sodium, potassium helps maintain extracellular fluid volume and facilitates nerve signaling, muscle contraction, and blood pressure control via the sodium-potassium pump mechanisms. Potassium also helps prevent muscle weakness and cramping.

Normal range: 3.6 to 5.5 mmol/L

Related conditions:

• Hypokalemia (low potassium) can lead to fatigue, muscle weakness, and, in severe cases, rhabdomyolysis if left untreated. It can also arise from malnutrition, diuretic use, kidney dysfunction, diarrhea or vomiting, and more.
• Hyperkalemia (high potassium) can also lead to muscle weakness and heart arrhythmias. It can result from cellular injury or kidney damage, which can negatively impact potassium excretion in the urine. Hyperkalemia is one of the most common electrolyte imbalances in people with chronic kidney disease.

Magnesium

What it is: Magnesium is a mineral from food, including green leafy vegetables, nuts, seeds, whole grains, and legumes. It’s crucial for bone and tooth health.

How it works: This electrolyte is a cofactor in more than 300 enzyme systems that regulate protein synthesis, heart rate and rhythm, blood pressure, muscle and nerve function, and metabolic processes like glucose control, insulin sensitivity, and energy production. Magnesium works to stabilize enzymes by influencing a particular conformation (shape) so ATP production can occur. By interacting with cell membrane proteins, magnesium also helps transport other electrolytes—primarily sodium, potassium, and calcium—across cell membranes to help manage fluid balance.

Normal range: 1.5 to 2.6 milligrams per deciliter (mg/dL)

Related conditions:

• Hypomagnesemia (low magnesium) can occur due to too little dietary intake or certain gastrointestinal conditions. It is often seen concurrently with low calcium and low potassium. Deficiency can cause muscle spasms and weakness, headaches, and heart arrhythmias. Low magnesium levels are also linked with Type 2 diabetes and might worsen insulin resistance since enzymes involved in regulating glucose metabolism and insulin signaling need magnesium to function properly. Worse, high blood sugar and insulin resistance can reduce kidney reabsorption of magnesium, leading to even lower levels.
• Hypermagnesemia (high magnesium) generally results from kidney disease, though hypothyroidism, hyperparathyroidism, adrenal insufficiency, and some medications and genetic conditions can also lead to the condition. Hypermagnesemia can cause problems with reflexes, confusion, arrhythmias, and—if not addressed—cardiac arrest.

Calcium

What it is: Calcium is most associated with bone and tooth health. It’s also crucial for muscle contraction, nerve signal transmission, blood clotting, hormonal secretion, enzyme functioning, and heart rhythm. We get most of our calcium from our diet.

How it works: For muscle contraction, when the sodium-potassium pump produces an action potential, the change results in the release of calcium stored in the sarcoplasmic reticulum, a network of tubules and sacs in skeletal muscle cells. This calcium then binds to proteins that regulate muscle contraction. After contraction, the sarcoplasmic reticulum reabsorbs the calcium to trigger muscle relaxation.

Additionally, calcium channels on smooth muscle membranes allow calcium to enter a cell. Both action potentials and calcium entering cells are essential for heart muscle contraction and the communication between heart cells. Calcium ions also indirectly support the sodium-potassium pump by altering cell membrane permeability to help manage these electrolytes. And calcium ions are required for the activation of blood clotting factors.

Normal range: In adults, 8.8 to 10.7 (mg/dL)

Related conditions:

• Hypocalcemia (low calcium) often causes no symptoms but may cause confusion and muscle weakness. Conditions that can cause hypocalcemia include Vitamin D deficiency, pancreatitis, severe illness or trauma, some cancers, imbalances in the electrolytes magnesium or phosphate, and conditions affecting the parathyroid. Taking some medications can also interfere with calcium balance.
• Hypercalcemia (high calcium) may cause fatigue, weakness, constipation, and bone pain. Excessive intake of Vitamin D or A conditions affecting the parathyroid, some cancers, and more can cause hypercalcemia.

Phosphate

What it is: Phosphate is the main form of the element phosphorus in the human body. Phosphorus is a mineral found in dairy products, nuts, seeds, meat, fish, legumes, and whole grains. Phosphate is crucial for bone and tooth health, fluid balance, pH balance, ATP production, cellular function, kidney function, and more.

How it works: When dissolved in water, phosphate is a negatively charged ion. It acts as a buffer, neutralizing excess acids or bases to maintain pH balance. Changes in phosphate concentration impact osmotic pressure to draw or shift fluid across cell membranes.

Normal range: 3.4 to 4.5 mg/dL

Related conditions:

• Hypophosphatemia (low phosphate) often results from kidney problems, but nutrient absorption issues, hyperparathyroidism, and refeeding syndrome (switching from starvation to replenishment) can also cause the condition. Hypophosphatemia can lead to muscle weakness, anemia, confusion, and, when severe, rhabdomyolysis and kidney damage.
• Hyperphosphatemia (high phosphate) most commonly occurs with kidney failure, but parathyroid issues can also cause the condition. It doesn’t tend to cause direct symptoms, though people may experience symptoms from underlying causes. Hyperphosphatemia increases the risk of MetS and cardiometabolic disorders and impairs insulin secretion. This may be due to high phosphate levels contributing to chronic low-grade inflammation, hardening the artery walls, and inhibiting pancreatic cells’ ability to release insulin.

Chloride

What it is: Chloride is a mineral we get mostly from table salt, though it’s also present in small amounts in seaweed, rye, lettuce, tomatoes, olives, celery, some fruits, seafood, and red meats. It’s crucial for maintaining healthy fluid levels and regulating blood pressure. Plus, it helps keep the body’s acid-base balance, which is necessary for the proper function of nearly all physiological processes, including digestion and nutrient absorption.

How it works: Chloride helps regulate osmotic pressure—controlling the movement and volume of water between cells. In your digestive tract, chloride combines with hydrogen to form hydrochloric acid in your stomach, enabling proper digestion and nutrient absorption. In your blood, it plays a vital role in acid-base balance, helping to transport carbon dioxide and maintain proper pH. Your kidneys carefully regulate chloride levels, making blood chloride an indicator of both kidney function and overall fluid and electrolyte balance.

Normal range: 97 to 105 mmol/L

Related conditions:

• Hypochloremia (low chloride) may result from fluid loss from diarrhea, vomiting, sweating, or taking diuretics, heart failure, kidney problems, or cystic fibrosis. It can also cause weakness, heart arrhythmias, muscle twitching or cramping, and gastrointestinal issues.
• Hyperchloremia (high chloride) can be caused by dehydration, kidney disease, metabolic acidosis, certain medications, or low bicarbonate, another imbalanced electrolyte. The condition can lead to nausea, vomiting, and muscle weakness.

Bicarbonate

What it is: Bicarbonate is a chemical compound (rather than a mineral) that’s a byproduct of the body metabolizing carbon dioxide. Along with chloride, it helps maintain the body’s acid-base balance, and plays a role in transporting carbon dioxide.

How it works: During cellular respiration, the body breaks down glucose into carbon dioxide, water, and ATP. In the bloodstream, the enzyme carbonic anhydrase converts that carbon dioxide to hydrogen and bicarbonate. The bicarbonate travels through the blood to the lungs, where it’s converted back into carbon dioxide and exhaled. This process regulates the body’s pH balance. Proper pH balance is necessary for nearly all physiological processes; it ensures enzymes and cellular activity function properly and delivers oxygen throughout the body.

Normal range: 22 to 29 mmol/L

Related conditions:

• Metabolic acidosis (low levels) can be caused by kidney disease or diarrhea. Symptoms may include fatigue, confusion, and nausea.
• Metabolic alkalosis (high levels) can be caused by kidney problems, chronic vomiting, cystic fibrosis, and certain genetic diseases, such as Bartter or Gitelman syndrome. Symptoms include confusion, muscle twitching, and arrhythmias.

Anion gap

What it is: Anion gap is a calculation to assess pH balance in relation to electrolyte balance in the blood. It helps determine whether your blood is too acidic or too alkaline.

How it works: Electrolytes either have a positive or negative charge. Anion gap calculates the difference between your blood’s positively and negatively charged ions. The higher the anion gap, the more acidic the blood; the lower the anion gap, the more alkaline the blood.

Normal range: Different labs present different “normal” ranges, based on the type of calculation. 4 to 12 mmol/L is a common reference range.

Related conditions:

• A low anion gap is rare but could indicate alkalosis, where the blood is too alkaline. This can occur if you ingest too much baking soda or antacids, vomit excessively, use diuretics, or have hypochloremia or hypokalemia. A kidney issue can also cause alkalosis.
• A high anion gap could indicate acidosis (high acid), which can signal dehydration, severe diarrhea, or lactic acid accumulation from liver failure, cancer, alcohol abuse, or intense or prolonged physical activity. But acidosis can also be an indicator of salicylate poisoning from too much aspirin, kidney disease, or complications from the conditiondiabetic ketoacidosis).

Is electrolyte supplementation a good idea?

We get electrolytes from food or drink; however, some people may need electrolyte supplementation for certain situations, including prolonged physical activity, heat stress, diuretic use, or other medical conditions. Before supplementing, talk to your doctor, especially if you’ve had an abnormal electrolyte test, have underlying conditions (including kidney, liver, or heart disease), or take any medications.

Electrolyte supplementation comes in many forms, including:

• Sports drinks, which typically contain a mix of sodium and potassium
• Powdered packets that you add to water, which often contain sodium, potassium, and magnesium
• Individual tablets or pills containing one electrolyte

The downside to drinks and packets is the added sugars. For example, traditional Gatorade and Powerade contain 21 grams of added sugars per 12-ounce serving, and traditional Liquid I.V. packets contain 11 grams per 16-ounce serving. Added sugars provide no nutritional value, and consuming them can increase your risk of Type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease (NAFLD), and obesity.

If you choose a drink or packet, look for one that is unsweetened (such as unflavored LMNT) or sweetened with stevia, a natural sweetener that doesn’t raise blood glucose.

You may need a supplement if:

1. You eat a very low-carb diet

You may not get enough sodium from food if you eat a low-carbohydrate diet, generally defined as consuming fewer than 130 grams of carbs daily. Cutting back this much on carbs reduces insulin levels, which can reduce the kidneys’ ability to reabsorb sodium.

2. You sweat a lot

We lose fluid and electrolytes through sweat. Whether and what you need to replenish is highly individual, based on activity duration, the temperature, and your diet. Talking to a doctor to assess your particular needs can be helpful. The following are general guidelines from the American College of Sports Medicine (ACSM) for competitive events—modify for less intense activity:

• Stay hydrated and eat a balanced diet in the 24 hours before physical activity.
• Drink about 16 ounces of fluid in the two hours before exercise.
• During exercise, consume fluids at regular intervals (such as every 20 minutes) to replace sweat losses. Add electrolytes and carbohydrates if your activity is intense and lasts longer than an hour.
• Consume 20 to 24 ounces of fluid for each pound of weight lost during activity. You can gauge this by weighing yourself before and after exercise.

3. You live in or are visiting a hot climate

Since we sweat in hot weather, you may need more electrolytes if you spend time in the heat, especially if you work out outdoors. Be cautious when the season first brings hot weather before you’ve become more acclimatized, or if you’ve recently moved to or are visiting a warmer climate than you’re used to.

Electrolyte imbalances don’t necessarily mean you need supplements

Electrolytes power the body’s electrical system, managing fluid balance and facilitating nerve and muscle signaling, among other processes. You may wish to check your electrolyte levels to uncover any imbalances, which could indicate metabolic health dysfunction.

Be sure to interpret your results in the context of other labs and your individualized factors. A single, moderate out-of-range result may not be a cause for concern. But if additional testing confirms a chronic or severe imbalance, a clinician can guide you regarding next steps, such as investigating or treating an underlying condition. Whether you should incorporate supplements depends on your unique circumstances, including underlying conditions, medications, physical activity level, and climate.

Summary

Maintaining proper electrolyte balance is essential for everything from hydration and heart rhythm to metabolic and neurological health. While most people can meet their needs through food and fluids, certain conditions, medications, or lifestyle factors may increase your risk of imbalance. Regular testing and individualized interpretation can help identify issues early and guide whether dietary adjustments or targeted supplementation are appropriate. Understanding your electrolyte status is a simple but powerful step toward optimizing overall metabolic health, brain health, and physical performance.

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