Electrolyte loss can lead to an imbalance in the blood's normal chemical makeup. Since a normal electrolyte balance is crucial to the body's function, imbalance can result in a variety of physiological dysfunctions, such as neurological impairment and heart rhythm disturbances. A common way to replace lost electrolytes is to eat or drink electrolyte-rich supplements such as sports drinks.
Purpose of Electrolytes
Electrolytes are charged particles normally obtained from the dissolved minerals we eat. Each cell in the body functions as a result of the difference in electrolyte concentrations on the inside vs. the outside of cell membranes. This electrolyte distribution across the membrane is similar to a power source for the cell, and the basic starting point for all chemical processes in the cell. It is for this fundamental reason that electrolyte balance in the body is so tightly regulated and why an imbalance can cause profound problems like water loss, heart arrhythmias and even death.
Electrolyte Regulation
The tight regulation of the body's electrolytes and water is one of the prime functions of the kidneys. Kidneys are designed like a check valve for the body's blood chemistry. Key electrolytes, such as sodium, potassium, calcium and chloride, are especially important to regulate since they have marked effects on cells that rely on electrical impulses to function, such as cardiac and nerve cells. Not only are the total amounts of electrolytes and water closely regulated, but also the amount of one electrolyte relative to another. When the blood level of a certain electrolyte is low, the kidneys are able to slow down the electrolyte excretion in the urine. This enables retention of that electrolyte along with water. Conversely, with a higher blood electrolyte level, the kidneys can accelerate its excretion. Electrolyte and water balance is therefore kept constant by the kidneys.
Heart Rhythm
The heart is a muscular pump controlled by electrical activity. Normal cardiac rhythm is when heartbeats are regular. When they become irregular or abnormal, the condition is known as arrhythmia. Many things can cause arrhythmias, such as disease, injury, valve disorders, high blood pressure and electrolyte imbalance. When due to electrolyte imbalance, arrhythmias can occur because cardiac cell activity is affected by the amount and ratio of electrolytes in and around the heart. An imbalance between sodium and potassium, for example, will cause cardiac cells to beat irregularly.
Electrolyte Imbalance and Supplements
When one or more electrolytes become depleted, as may occur with extreme exercise or disease, the overall electrolyte balance is disturbed. The normal serum sodium level is 135 to 145 mEq per liter, while potassium is 3.5 to 5.0 mEq per liter. According to the book "Pediatric Critical Care Medicine," when the amounts of these electrolytes fall below these levels, the heart can undergo electrical changes and produce arrhythmias. Depending on the amount of electrolyte depletion, the arrhythmias can be severe and even life threatening. Immediate replacement with foods or drinks rich in electrolytes can usually restore the normal balance unless a disease such as renal failure prevents it.
References
- Cleveland Clinic: Diseases and Conditions: Management of Arrhythmias
- "Pediatric Critical Care Medicine"; Fluid Management and Electrolyte Disturbances; A. Kalia and A Sharma; 2006
- American Family Physician: Diagnostic Approach to Palpitations
