Signs and Symptoms of Low Potassium

The normal potassium level in the blood is 3.5 to 5.0 mEq/L (milliequivalent per liter). Any level below 3.5 mEq/L is called "low potassium level". Out of every five people hospitalized in the United States, one has a low potassium level. When the potassium level drops to less than 2.5 mEq/L then the condition is life-threatening and needs emergency medical attention. The effect of low potassium in the body is the formation of a potentially fatal state called "Hypokalemia". Severe condition of this disease leads to the following conditions.

Effects of Low Potassium

• Cardiac arrhythmia (irregular heartbeat)
• Muscle weakness and myalgia
• Disturbed heart rhythm
• More risk of hyponatremia with confusion and seizures

Low Potassium Symptoms

The symptoms of low potassium are usually mild and at times, vague. It is not unusual to have more than one symptom concerning the kidneys, muscles, nerves, heart and gastrointestinal tract. Some of the common symptoms are:

• Weakness or tiredness
• Cramping in arm and weakness in legs
• Abdominal cramping or bloating
• Nausea or vomiting
• Tingling or numbness
• Passing large quantity of urine or a frequent sensation of thirst
• Irregular psychological behavior like depression, psychosis, delirium, confusion or seeing or hearing things (hallucinations)
• Fainting due to low blood pressure
• Palpitations
• Constipation
• Abnormal heart rhythm (arrhythmia)

Severe hypokalemia is not linked with any symptoms, but it may cause:

• Muscle weakness - inability to exert force with one's muscles to the expected degree
• Myalgia or muscle pain
• Disturbed heart rhythm including cardiac ectopy (disturbance of the electrical conduction system of the heart where beats arise from the wrong part of the heart muscle)
• Serious arrhythmia (electrical activity of the heart is irregular i.e. faster or slower than normal)
• Greater risk of hyponatremia (an electrolyte disturbance in blood when the sodium concentration in the plasma decreases below 135 mmol/L) with confusion and seizures

The changes in the electrocardiogram pertaining to hypokalemia are:

• U waves
• Flattened (notched) T waves
• ST depression
• Prolonged QT interval

Potassium is an electrolyte present in the intracellular fluid and is present in abundant quantity. It regulates the neuromuscular activity of the skeletal, cardiac and smooth muscle. So, when the potassium level becomes low, it results in muscle malfunction and muscle twitching. Also, the heart contracts prematurely, as the muscles that assist in breathing become weak and lead to respiratory arrest. The kidneys become unable to concentrate urine and this leads to excessive urination and thirst. The bowel motility is also hindered. If it becomes very slow, there may be signs of a paralytic ileus. This means that the intestines are somewhat paralyzed due to a decrease in the peristalsis. Sometimes, low potassium leads to anorexia. In this, there is a decreased sensation of appetite. Presence of adrenal tumors and hypertension cause the renal potassium stores to be depleted and make the person susceptible to hypokalemia. Use of chemotherapy also causes hypokalemia.

Sometimes, bodybuilders take diuretics before competition to get rid of excess water. This throws out electrolytes from their body. This causes the potassium level to get dangerously low. If this condition is accompanied by starvation, then there may be a number of physical problems as well as hypokalemia. Infants and young children having gastrointestinal ailments that lead to prolonged vomiting and diarrhea, can die due to cardiac arrest when the potassium level becomes very low. This is because large quantity of potassium is present in gastric fluids and this is lost during vomiting.