Electrolytes are substances that have a positive or negative charge when dissolved in water. Common electrolytes in the human body are sodium, potassium, magnesium, and calcium. These are vital for maintaining a neutral charge in our cells, carrying out biochemical and enzymatic reactions, and conducting impulses that allow our muscles and nerves to function correctly.
Keep reading to learn more about electrolytes, signs of electrolyte imbalance, and how to ensure you're getting adequate electrolyte intake.
What are Electrolytes?
Electrolytes are minerals in the body that have a positive or negative charge and are present in the tissues, blood, urine, and other body fluids. They are essential to many basic body functions, such as:
- Ensuring that nerves, muscles, the heart, and the brain function properly
- Maintaining electrical neutrality in cells
- Balancing the amount of water in the body
- Balancing the body's pH (acidity) level
- Moving nutrients into the cells
- Moving wastes out of the cells
We absorb electrolytes from the food and fluids we consume and lose them via our urine or through sweating. Since electrolytes are essential, ensuring our body gets the correct quantity needed to function optimally is critical.
Types of Electrolytes
We need individual electrolytes in different amounts, and although they work together synergistically, they each have unique roles.
Sodium, a positively charged electrolyte, is one of the most important in our body. It helps to maintain the fluid volume that bathes our cells and ensures the correct electrical charge is maintained across our cell membranes. The kidneys regulate sodium levels.
Potassium, present in many foods, is another positively charged electrolyte. Our bodies need potassium for almost every function, including kidney and heart function, nerve transmission, and muscle contraction. If you have an inflammatory bowel disease or take certain medications (including diuretics like furosemide or hydrochlorothiazide), you may have difficulty getting enough potassium through food intake alone.
Magnesium is a positively charged electrolyte that is abundant inside our cells. It is needed for hundreds of biochemical reactions in the body and helps to maintain normal nerve and muscle function, supports a healthy immune system, keeps a steady heartbeat, and helps maintain the strength of our bones. It also helps normalize blood glucose levels.
Calcium, another positively charged mineral, is the most abundant electrolyte in the body and thus has critical physiological roles. We need calcium for several functions, such as conducting nerve impulses, secretion of hormones, supporting bone mineralization, keeping tissues healthy and flexible, maintaining the structure and strength of teeth and connective tissue, and triggering the contraction and dilation of blood vessels. Calcium is also a vital cofactor that allows our blood to clot properly. Calcium is obtained primarily through the diet, where Vitamin D controls intestinal absorption.
Electrolyte Imbalance Symptoms
Our bodies tightly regulate electrolyte levels, but sometimes levels can get too high or too low, leading to an imbalance.
Hyponatremia (low sodium level) is the most common among electrolyte disorders. Causes of hyponatremia include an underlying medical condition like kidney disease or congestive heart failure, certain medications, or drinking too much water, all of which can cause the sodium in our body to become diluted. Hyponatremia has neurological manifestations such as headaches, nausea, confusion, and delirium and can lead to coma and death if severe enough and not treated promptly.
The opposite of hyponatremia is hypernatremia (high sodium levels). People most at risk for developing this condition are adults over 65 years with mental or physical impairments that make it difficult to drink enough water. Diabetes insipidus and certain medications (a common culprit is the psychiatric medication lithium) can also cause high sodium levels. Symptoms of hypernatremia include irritability and confusion, extreme thirst, and restlessness that can progress to seizures and loss of consciousness.
Hypokalemia (low potassium levels) occurs most commonly from medications like diuretics that cause loss of potassium in the urine. Symptoms of hypokalemia include fatigue, weakness, muscle twitching, and heart rhythm changes.
The opposite of hypokalemia is hyperkalemia (high potassium levels). Sometimes, a lab mistake can cause a false elevation of the potassium level; this is common in clinical practice. True causes of elevated potassium include kidney disease and medications like spironolactone or blood pressure medications called ACE inhibitors. Symptoms of hyperkalemia include weakness, paralysis, and heart rhythm changes.
Hypomagnesemia (low magnesium levels) often occurs concurrently with low calcium and potassium. Causes include:
- Inadequate dietary intake.
- Magnesium loss through bowel movements or in the urine.
- Alcohol use coupled with poor nutrition.
Symptoms of hypomagnesemia include:
- Muscle spasms that can increase in intensity to a prolonged spasm called tetany.
- Abnormal eye movements (nystagmus).
- Fatigue and weakness.
Severe cases of hypomagnesemia can progress to seizures and a state of delirium. Low magnesium levels are also associated with a specific type of cardiac arrhythmia called Torsade de Pointes.
The opposite of hypomagnesemia is hypermagnesemia (high magnesium levels); this is an uncommon electrolyte imbalance. It occurs primarily in patients with acute or chronic kidney disease. People with inflammatory bowel disease, slow gut motility, or opioid use may absorb excess magnesium, which can (rarely) lead to clinically relevant hypermagnesemia. Symptoms of this imbalance include gastrointestinal complaints like nausea and diarrhea, drowsiness, floppy muscles with poor reflexes, low blood pressure, and slow heart rate. Coma and cardiac arrest can occur in severe cases.
Hypocalcemia (low calcium levels) is usually a result of a vitamin D deficiency, inadequate parathyroid hormone levels, hypomagnesemia, or kidney disease. Paradoxically, medications, such as bisphosphonates and denosumab for the prevention and treatment of osteoporosis, can also cause hypocalcemia. Healthcare providers should evaluate calcium and vitamin D levels before starting these medications.
Osteoporosis is one of the best-known conditions that long-term calcium deficiency, in addition to other factors, causes. This condition can lead to hip fractures, vertebral compression fractures, and falls.
Mild hypocalcemia can be asymptomatic.
Moderate hypocalcemia can cause:
- Muscle cramps
- Brittle nails
- New onset coarse hair
- Scaly, dry skin
As hypocalcemia worsens, other findings begin to present:
- Muscle spasms in specific locations (Chvostek's and Trousseau's signs)
- Memory loss
Severe, life-threatening hypocalcemia can cause:
- Tingling around the lips and tongue, as well as distal extremities
- Spasms in the throat muscles that make breathing difficult
- Prolonged muscle spasms called tetany
Hypocalcemia can lead to seizures, heart rhythm disturbances, coma, and death.
The opposite of hypocalcemia is hypercalcemia (high calcium levels). Overactive parathyroid glands usually cause hypercalcemia. Cancers, such as lung and breast cancer, can also lead to hypercalcemia. Other causes of hypercalcemia include certain medications and excessive supplementation with vitamin D and calcium (often in the form of over-the-counter antacids). Signs and symptoms of hypercalcemia include bone pain, kidney stones, increased urination and thirst, constipation, cognitive changes, and muscle cramps or twitches.
How to Monitor Electrolyte Levels
Blood tests can easily measure electrolytes. You can measure common electrolytes like sodium, potassium, and total serum calcium in a comprehensive metabolic panel.
In addition, you can evaluate electrolytes individually:
- Serum calcium: If the patient's albumin levels are abnormal, then the total serum calcium measurement can be inaccurate
- Ionized calcium is preferred in the case of abnormal albumin levels
- Serum magnesium: If you have a high index of suspicion for a magnesium deficiency, then an RBC magnesium may be more accurate
- Serum potassium
- Serum sodium
How to Increase Electrolyte Intake
Dehydration can cause electrolyte imbalances. In most instances, water is the best way to replace lost fluids. However, if you exercise or train for more than 60 minutes, a sports drink can deliver essential nutrients to help maintain the body's electrolyte balance.
There are plenty of ways to obtain the body's needed electrolytes through diet alone.
Dairy products are a fantastic source of calcium. As little as 1 cup (240 ml) of milk contains 199 mg (20% DV) of calcium and 281 mg (8% DV) of potassium.
Electrolytes are a crucial part of an individual's chemical composition. Electrolytes are vital for optimally functioning cells, tissues, nerves, and muscles. A balance of different electrolytes is critical for the body to function. An electrolyte imbalance can affect the body's performance and lead to various symptoms. Healthcare providers can assess the electrolyte status of an individual with lab tests. Consuming electrolytes during or after intense exercise and other periods of increased sweating can help preserve balance.