Potassium, a mineral abundant in a normal diet, functions as an electrolyte in your body. Electrolytes conduct electrochemical signals that regulate many functions in your body, including those of muscle and nerve cells, as MayoClinic.com explains. A significantly decreased potassium level leads to serious complications. Luckily, decreased body potassium -- hypokalemia -- that reaches low enough values to present serious danger is rare. Nutritional deficits alone will generally not drop levels into the danger zone.
Irregular Heart Rhythm
Certain medical conditions and medications such as diuretics and laxatives can, however, promote enough excretion through urine and stool to reach a critically low level. Your heart uses potassium in the conducting system that regulates and maintains a regular heart rate. "Brenner and Rector's: The Kidney, 8th edition" explains that when potassium reaches very low levels, conduction becomes disordered, resulting in an arrhythmia -- an irregular heart rhythm. If you are taking diuretics for a heart condition, you should have your potassium level checked as recommended by your doctor. If you take digitalis, commonly used to treat heart failure and abnormal heart rhythms, you need to have your potassium level followed much more closely. A prescribed supplement tablet raises potassium back into normal range for most people.
Muscle Weakness and Cramps
Mild hypokalemia causes almost no symptoms. If your potassium drops into the moderately low range, muscle weakness and cramps become problematic. In critical illness, potassium intake decreases, and a variety of mechanisms increase potassium losses from your body. If this situation becomes severe and longstanding, the possibility of paralysis and respiratory failure occurs, as noted in the "Critical Care Clinics" medical journal in its April 2002 issue.
Constipation
Coordinated contractions of bowel -- called peristalsis -- which move food along your digestive tract to allow elimination of stool, also requires potassium, explains The Merck Manual of Health and Aging. Constipation, another symptom of hypokalemia, occurs when this process slows down. If you take laxatives to relieve the constipation, potassium levels drop even further. This could initiate a cycle of constipation and laxative use, causing potassium to reach critically low levels.
Fatigue
Fatigue represents one of the most commonly reported, but also the most nonspecific, symptoms of low potassium. Of course, fatigue has many possible causes and does not confirm a diagnosis of hypokalemia. A blood test quickly checks potassium and other electrolyte levels. If you have severe fatigue or any symptom of hypokalemia, only your doctor can help you figure out the diagnosis. The Internet should not be used to diagnose or treat any condition and is for informational purposes only.
References
- MayoClinic.com: Low Potassium (Hypokalemia)
- "Critical Care Clinics"; Disorders of Potassium Homeostasis: Hypokalemia and Hyperkalemia; F. John Gennari, M.D.; April 2002
- The Merck Manual of Health and Aging: Problems With Electrolyte Balance
- "Brenner and Rector's: The Kidney, 8th edition"; Barry M. Brennar, M.D., editor; 2007
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