Potassium is an electrolyte essential for muscle function. Too much or too little potassium in your bloodstream causes problems with the skeletal muscle that moves your body, the smooth muscle in your digestive system and arteries, and the cardiac muscle in your heart. Too little potassium, or hypokalemia, can cause muscle cramps. Too much potassium, or hyperkalemia, can cause muscle cramps, weakness or paralysis. Severe hyperkalemia is potentially life threatening because its effect on the cardiac muscle can cause the heart to stop.
Causes of Hyperkalemia
Hyperkalemia is often the result of improper management of prescription medications, since some diuretics and blood pressure medications can affect the level of potassium in your blood. Chronic kidney failure also causes hyperkalemia, since one of your kidneys' functions is to maintain proper electrolyte levels in your blood. Lack of the hormone aldosterone caused by disorders such as Addison's disease can also cause hyperkalemia. Other causes include rhabdomyolysis, critical burns, gastrointestinal bleeding or some types of tumors.
Potassium and Muscle Function
Potassium is one of the key electrolytes involved in muscle function. Your body's smooth muscle, skeletal muscle and cardiac muscle all need potassium to work. Electrolytes get their name because they have an electrical charge, so they change the charge of your nerve cells when thy move into or out of them. When a nerve cell reaches a certain charge, it "fires" and sends a chemical message to your muscle, causing it to contract. If you have too much potassium in your blood, nerve cells can become "irritable" and send confused messages to your muscles, causing them to cramp.
Symptoms of Hyperaklemia
Muscle cramps are a symptom of hyperkalemia because of potassium's effects on skeletal muscle. Abdominal cramping and nausea occur because of potassium's effects on smooth muscle. Other symptoms include numbness or tingling sensations, fatigue, muscle weakness, dizziness and diarrhea. Severe hyperkalemia can lead to muscle paralysis, irregular heartbeat or death.
Avoiding or Treating Hyperkalemia
To prevent hyperkalemia, take all prescription medicines correctly. If you take a medication that can alter blood potassium, allow your physician to perform regular blood tests to monitor your potassium levels. If your doctor diagnoses hyperkalemia, he will probably admit you to the hospital so medical staff can monitor you closely during treatment. Treatments include cation-exchange resin medications to remove excess potassium from your blood, diuretics, intravenous calcium, intravenous glucose and insulin, sodium bicarbonate treatment, or dialysis. Treatment depends on the cause and severity of your hyperkalemia.