Potassium Deficiency And Muscle Tightness

Potassium is an electrolyte that is essential for the function of your nervous system, muscles, cardiovascular system and digestion. Too much or too little potassium can cause symptoms that vary from minor annoyances to life-threatening conditions. Muscle cramping is one of the symptoms of mild potassium deficiency. Your doctor will do a blood test if he or she thinks you might have a potassium deficiency, and prescribe supplements if necessary.

Causes of Potassium Deficiency

Potassium deficiency, or hypokalemia, can result from a diet that lacks fruits and vegetables. A diet too high in sodium or phosphates, like those found in soft drinks, can also cause low potassium. Dietary hypokalemia is usually mild. You lose potassium when you sweat, so excessive sweating from strenuous exercise or heat exposure can also cause hypokalemia. Severe vomiting or diarrhea, laxative abuse such as in some eating disorders, and certain medications such as some types of diuretics, can cause serious potassium deficiency. Your kidneys regulate the level of potassium in your blood, so chronic kidney failure can also lead to hypokalemia. A hormonal disorder called primary aldosteronism, chronic alcoholism and poorly controlled diabetes are some other causes of potassium deficiency.

Potassium and Muscle Function

As one of your body's essential electrolytes, potassium plays a key role in neuromuscular junction, in which your nerves communicate with your muscles. To "fire," or send signals to your muscles, nerve cells pump sodium from outside the cell into the cell, which changes the nerve cell's electrical charge. Once the cell's charge reaches a certain level, the cell fires and releases chemicals that signal your muscles to contract. After the cell fires, it pumps sodium and potassium out of itself to return its charge to a resting state and prepare to fire again. Potassium keeps the cell from firing again too soon. When your body lacks potassium, your nerve cells can become over-excitable and send too many signals to your muscles, causing them to cramp.

Symptoms of Potassium Deficiency

Hypokalemia causes problems with the smooth muscles in your digestive tract, which can cause nausea, lack of appetite and bloating. Prolonged potassium deficiency can contribute to high blood pressure. Acute hypokalemia's effects on your nervous system can cause lightheadedness, low blood pressure, muscle cramps, weakness and heart rhythm problems. Muscle cramps caused by hypokalemia are usually in the legs.

Preventing or Treating Potassium Deficiency

You can avoid dietary potassium deficiency by eating a diet that includes potassium-rich foods such as bananas, potatoes, oranges and dairy products. Experts at the Colorado State University Extension recommend 4,700 milligrams per day of dietary potassium. Avoiding too much sodium or phosphates, which are found in sodas and processed food such as cured meats, can also help keep your potassium levels in the healthy range. If you take a medication that can cause hypokalemia, your doctor will use blood tests to monitor your potassium levels and prescribe supplements if needed. Never take more than the recommended dose of supplements that contain potassium because too much potassium is just as harmful as too little, and potassium overdose is potentially fatal.