Serum Electrolytes (Na, K, Cl)

Serum Electrolytes are substances that have a natural positive or negative electrical charge when dissolved in water. They help your body regulate chemical reactions, maintain the balance between fluids inside and outside your cells, and more. They’re also a key way to diagnose a wide range of medical conditions and diseases.

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.

Understanding electrolyte disorders

Electrolytes are elements and compounds that occur naturally in the body. They control important physiologic functions.

Examples of electrolytes include:

• calcium
• chloride
• magnesium
• phosphate
• potassium
• sodium

These substances are present in your blood, bodily fluids, and urine. They’re also ingested with food, drinks, and supplements.

An electrolyte disorder occurs when the levels of electrolytes in your body are either too high or too low. Electrolytes need to be maintained in an even balance for your body to function properly. Otherwise, vital body systems can be affected.

Severe electrolyte imbalances can cause serious problems such as coma, seizures, and cardiac arrest.

Symptoms of electrolyte disorders

Mild forms of electrolyte disorders may not cause any symptoms. Such disorders can go undetected until they’re discovered during a routine blood test. Symptoms usually start to appear once a particular disorder becomes more severe.

Not all electrolyte imbalances cause the same symptoms, but many share similar symptoms.

Common symptoms of an electrolyte disorder include:

• irregular heartbeat
• fast heart rate
• fatigue
• lethargy
• convulsions or seizures
• nausea
• vomiting
• diarrhea or constipation
• abdominal cramping
• muscle cramping
• muscle weakness
• irritability
• confusion
• headaches
• numbness and tingling

Call your doctor right away if you’re experiencing any of these symptoms and suspect you might have an electrolyte disorder. Electrolyte disturbances can become life-threatening if left untreated.

Causes of electrolyte disorders

Electrolyte disorders are most often caused by a loss of bodily fluids through prolonged vomiting, diarrhea, or sweating. They may also develop due to fluid loss related to burns.

Certain medications can cause electrolyte disorders as well. In some cases, underlying diseases, such as acute or chronic kidney disease, are to blame.

The exact cause may vary depending on the specific type of electrolyte disorder.

Types of electrolyte disorders

Elevated levels of an electrolyte are indicated with the prefix “hyper-.” Depleted levels of an electrolyte are indicated with “hypo-.”

Conditions caused by electrolyte level imbalances include:

• calcium: hypercalcemia and hypocalcemia
• chloride: hyperchloremia and hypochloremia
• magnesium: hypermagnesemia and hypomagnesemia
• phosphate: hyperphosphatemia or hypophosphatemia
• potassium: hyperkalemia and hypokalemia
• sodium: hypernatremia and hyponatremia

Calcium

Calcium is a vital mineral that your body uses to stabilize blood pressure and control skeletal muscle contraction. It’s also used to build strong bones and teeth.

Hypercalcemia occurs when you have too much calcium in the blood. This is usually caused by:

• kidney disease
• thyroid disorders, including hyperparathyroidism
• lung diseases, such as tuberculosis or sarcoidosis
• certain types of cancer, including lung and breast cancers
• excessive use of antacids and calcium or vitamin D supplements
• medications such as lithium, theophylline, or certain water pills

Hypocalcemia occurs due to a lack of adequate calcium in the bloodstream. Causes can include:

• kidney failure
• hypoparathyroidism
• vitamin D deficiency
• pancreatitis
• prostate cancer
• malabsorption
• certain medications, including heparin, osteoporosis drugs, and antiepileptic drugs

Chloride

Chloride is necessary for maintaining the proper balance of bodily fluids.

Hyperchloremia occurs when there’s too much chloride in the body. It can happen as a result of:

• severe dehydration
• kidney failure
• dialysis

Hypochloremia develops when there’s too little chloride in the body. It’s often caused by sodium or potassium problems.

Other causes can include:

• cystic fibrosis
• eating disorders, such as anorexia nervosa
• scorpion stings
• acute kidney failure

Magnesium

Magnesium is a critical mineral that regulates many important functions, such as:

• muscle contraction
• heart rhythm
• nerve function

Hypermagnesemia means excess amounts of magnesium. This disorder primarily affects people with Addison’s disease and end-stage kidney disease.

Hypomagnesemia means having too little magnesium in the body. Common causes include:

• alcohol use disorder
• malnutrition
• malabsorption
• chronic diarrhea
• excessive sweating
• heart failure
• certain medications, including some diuretics and antibiotics

Phosphate

The kidneys, bones, and intestines work to balance phosphate levels in the body. Phosphate is necessary for a wide variety of functions and interacts closely with calcium.

Hyperphosphatemia can occur due to:

• low calcium levels
• chronic kidney disease
• severe breathing difficulties
• underactive parathyroid glands
• severe muscle injury
• tumor lysis syndrome, a complication of cancer treatment
• excessive use of phosphate-containing laxatives

Low levels of phosphate, or hypophosphatemia, can be seen in:

• acute alcohol abuse
• severe burns
• starvation
• vitamin D deficiency
• overactive parathyroid glands
• certain medications, such as intravenous (IV) iron treatment, niacin (Niacor, Niaspan), and some antacids

Potassium

Potassium is particularly important for regulating heart function. It also helps maintain healthy nerves and muscles.

Hyperkalemia may develop due to high levels of potassium. This condition can be fatal if left undiagnosed and untreated. It’s typically triggered by:

• severe dehydration
• kidney failure
• severe acidosis, including diabetic ketoacidosis
• certain medications, including some blood pressure medications and diuretics
• adrenal insufficiency, which is when your cortisol levels are too low

Hypokalemia occurs when potassium levels are too low. This often happens as a result of:

• eating disorders
• severe vomiting or diarrhea
• dehydration
• certain medications, including laxatives, diuretics, and corticosteroids

Sodium

Sodium is necessary for the body to maintain fluid balance and is critical for normal body function. It also helps to regulate nerve function and muscle contraction.

Hypernatremia occurs when there’s too much sodium in the blood. Abnormally high levels of sodium may be caused by:

• inadequate water consumption
• severe dehydration
• excessive loss of bodily fluids as a result of prolonged vomiting, diarrhea, sweating, or respiratory illness
• certain medications, including corticosteroids

Hyponatremia develops when there’s too little sodium. Common causes of low sodium levels include:

• excessive fluid loss through the skin from sweating or burns
• vomiting or diarrhea
• poor nutrition
• alcohol use disorder
• overhydration
• thyroid, hypothalamic, or adrenal disorders
• liver, heart, or kidney failure
• certain medications, including diuretics and seizure medications
• syndrome of inappropriate secretion of antidiuretic hormone (SIADH)

Diagnosing electrolyte disorders

A simple blood test can measure the levels of electrolytes in your body. A blood test that looks at your kidney function is important as well.

Your doctor may want to perform a physical exam or order extra tests to confirm a suspected electrolyte disorder. These additional tests will vary depending on the condition in question.

For example, hypernatremia (too much sodium) can cause loss of elasticity in the skin due to significant dehydration. Your doctor can perform a pinch test to determine whether dehydration is affecting you.

They may also test your reflexes, as both increased and depleted levels of some electrolytes can affect reflexes.

An electrocardiogram (ECG or EKG), an electrical tracing of your heart, may also be useful to check for any irregular heartbeats, rhythms, or ECG or EKG changes brought on by electrolyte problems.

Treating electrolyte disorders

Treatment varies depending on the type of electrolyte disorder and on the underlying condition that’s causing it.

In general, certain treatments are used to restore the proper balance of minerals in the body. These include:

Intravenous (IV) fluids

Intravenous (IV) fluids, typically sodium chloride, can help rehydrate the body. This treatment is commonly used in cases of dehydration resulting from vomiting or diarrhea. Electrolyte supplements can be added to IV fluids to correct deficiencies.

Certain IV medications

IV medications can help your body restore electrolyte balance quickly. They can also protect you from negative effects while you’re being treated by another method.

The medication you receive will depend on the electrolyte disorder you have. Medications that may be administered include calcium gluconate, magnesium chloride, and potassium chloride.

Oral medications and supplements

Oral medications and supplements are often used to correct chronic mineral abnormalities in your body. This is more common in if you’ve been diagnosed with ongoing kidney disease.

Depending on your electrolyte disorder, you may receive medications or supplements such as:

• calcium (gluconate, carbonate, citrate, or lactate
• magnesium oxide
• potassium chloride
• phosphate binders, which include sevelamer hydrochloride (Renagel), lanthanum (Fosrenol), and calcium-based treatments such as calcium carbonate

They can help replace depleted electrolytes on a short- or long-term basis, depending on the underlying cause of your disorder. Once the imbalance has been corrected, your doctor will treat the underlying cause.

Although some of the supplements can be purchased over the counter, most people with electrolyte disorders get a prescription for supplements from their doctor.

Hemodialysis

Hemodialysis is a type of dialysis that uses a machine to remove waste from your blood.

One way to get the blood to flow to this artificial kidney is for your doctor to surgically create a vascular access, or an entrance point, into your blood vessels.

This entrance point will allow a larger amount of blood to flow through your body during hemodialysis treatment. This means more blood can be filtered and purified.

Hemodialysis can be used when an electrolyte disorder is caused by sudden kidney damage and other treatments aren’t working. Your doctor may also decide on hemodialysis treatment if the electrolyte problem has become life-threatening.

Risk factors for electrolyte disorders

Anyone can develop an electrolyte disorder. Certain people are at an increased risk because of their medical history. Conditions that increase your risk for an electrolyte disorder include:

• alcohol use disorder
• cirrhosis
• congestive heart failure
• kidney disease
• eating disorders, such as anorexia and bulimia
• trauma, such as severe burns or broken bones
• thyroid disorders
• adrenal gland disorders

Preventing electrolyte disorders

Follow this advice to help prevent electrolyte disorders:

• stay hydrated if you’re experiencing prolonged vomiting, diarrhea, or sweating
• visit your doctor if you’re experiencing common symptoms of an electrolyte disorder

If the electrolyte disorder is caused by medications or underlying conditions, your doctor will adjust your medication and treat the cause. This will help prevent future electrolyte imbalances.

Fluids in your body

Athletes have been swigging electrolyte replenishers since 1965. That was the year a Florida Gators coach asked doctors why his players were wilting so quickly in the heat. Their answer? The players were losing too many electrolytes. Their solution was to invent Gatorade. So, what are electrolytes and why are they important?

Water and electrolytes are essential to your health. At birth, your body is about 75 to 80 percent water. By the time you’re an adult, the percentage of water in your body drops to approximately 60 percent if you’re male and 55 percent if you’re female. The volume of water in your body will continue to decrease as you age.

Fluid in your body contains things such as cells, proteins, glucose, and electrolytes. Electrolytes come from the food and liquids you consume. Salt, potassium, calcium, and chloride are examples of electrolytes.

Electricity and your body

Electrolytes take on a positive or negative charge when they dissolve in your body fluid. This enables them to conduct electricity and move electrical charges or signals throughout your body. These charges are crucial to many functions that keep you alive, including the operation of your brain, nerves, and muscles, and the creation of new tissue.

Each electrolyte plays a specific role in your body. The following are some of the most important electrolytes and their primary functions:

Sodium

• helps control fluids in the body, impacting blood pressure
• necessary for muscle and nerve function

Chloride

• helps balance electrolytes
• helps balance electrolytes
• balances acidity and alkalinity, which helps maintain a healthy pH
• essential to digestion

Potassium

• regulates your heart and blood pressure
• helps balance electrolytes
• aids in transmitting nerve impulses
• contributes to bone health
• necessary for muscle contraction

Magnesium

• important to the production of DNA and RNA
• contributes to nerve and muscle function
• helps maintain heart rhythm
• helps regulate blood glucose levels
• enhances your immune system

Calcium

• key component of bones and teeth
• important to the movement of nerve impulses and muscle movement
• contributes to blood clotting

Phosphate

• strengthens bones and teeth
• helps cells produce the energy needed for tissue growth and repair

Bicarbonate

• helps your body maintain a healthy pH
• regulates heart function

When electrolytes become unbalanced

Fluids are found inside and outside the cells of your body. The levels of these fluids should be fairly consistent. On average, about 40 percent of your body weight is from fluids inside the cells and 20 percent of your body weight is from fluids outside the cells. Electrolytes help your body juggle these values in order to maintain a healthy balance inside and outside your cells.

It’s normal for electrolyte levels to fluctuate. Sometimes, though, your electrolyte levels can become imbalanced. This can result in your body creating too many or not enough minerals or electrolytes. A number of things can cause an electrolyte imbalance, including:

• fluid loss from heavy exercise or physical activity
• vomiting and diarrhea
• medications such as diuretics, antibiotics, and chemotherapy drugs
• alcoholism and cirrhosis
• heart failure
• kidney disease
• diabetes
• eating disorders
• severe burns
• some forms of cancer

Preventing electrolyte imbalance

The International Marathon Medical Director’s Association offers the following guidelines for maintaining good hydration and electrolyte balance during activity:

• If your urine is clear to straw-colored before a race or workout, you’re well hydrated.
• You should drink a sports drink containing electrolytes and carbohydrates if your sporting event or workout lasts longer than 30 minutes.
• Drinking water with a sports drink decreases the beverage’s benefits.
• Drink when you’re thirsty. Don’t feel you must constantly replenish fluids.
• Although the needs of each individual differ, a general rule of thumb is to limit fluids to 4–6 ounces every 20 minutes of a race.
• Seek immediate medical advice if you lose more than 2 percent of your body weight or if you gain weight after running.

Serious emergencies from electrolyte imbalances are rare. But it’s important to your health and, if you’re an athlete, your performance to maintain a healthy electrolyte balance.

Symptoms of electrolyte imbalance

Symptoms of electrolyte imbalance vary depending on which electrolytes are most affected. Common symptoms include:

• nausea
• lethargy
• fluid retention

Treatment

Treatment is determined by the cause of the electrolyte imbalance, the severity of the imbalance, and by the type of electrolyte that’s either in short supply or overabundant. Treatment options normally include either increasing or decreasing fluid intake. Mineral supplements may be given by mouth or intravenously if depleted.

25 Foods That Replenish Electrolytes

Foods with electrolytes include:

• spinach
• kale
• avocados
• broccoli
• potatoes
• beans
• almonds
• peanuts
• soybeans
• tofu
• strawberries
• watermelon
• oranges
• bananas
• tomatoes
• milk
• buttermilk
• yogurt
• fish, such as flounder
• turkey
• chicken
• veal
• raisins
• olives
• canned foods, such as soups and vegetables

Food vs. drink

The amount of electrolytes you require on a daily basis varies and is based on several factors, including:

• age
• activity level
• water consumption
• climate

Most people get enough electrolytes from the daily foods and beverages they take in. In some instances, electrolyte beverages such as sports drinks may be a good way for you to quickly replace fluids, carbohydrates, and electrolytes that you lost during extreme activity.

Electrolytes leave the body through sweat and urine. If you sweat a lot, exercise in hot weather, or work out vigorously for more than an hour or two, you may benefit from drinking electrolyte beverages before, during, and after your workout.

People at risk for dehydration, such as those who have a high fever or diarrhea and vomiting, may also benefit from electrolyte beverages.