Hypokalemia is one of the most commonly encountered abnormality and it occurs when the level of serum potassium in the blood drops to < 3.5 mEq/L. It is characterized by potassium deficiency that can either be due to inadequate potassium intake or excessive potassium loss. Potassium plays one of the most important functions in the human body as it is required for the functions of the cells, especially nerves and muscles. It also regulates the water balance and acid-base balance in the blood and tissues. According to the research, the amount of potassium that is present in the human body is approximately 50 mEq/kg and of which, 90% of the potassium is found in the intracellular fluid, 8% is found in the skin and bones and 2% is found in the extracellular fluid. Maintaining the level of extracellular fluid is important and any fluctuations in it can lead to severe complications. Most of the total body potassium is present in the intracellular fluid and any changes in the distribution of potassium can alter the extracellular concentration. The decrease in the level of potassium can be defined as chronic hypokalemia and acute hypokalemia:
- Chronic hypokalemia can develop in weeks to months.
- Acute hypokalemia can develop in over hours to days.
Symptoms of Hypokalemia
Potassium is an essential mineral for the normal functioning of the human body and any imbalances or particularly decrease in the amount of potassium in the body can lead to many changes and causes many symptoms. Some of the symptoms of hypokalemia include:
- Muscle breakdown
- Digestive problems
- Muscle spasm
- Nausea and vomiting
Causes of Hypokalemia
Hypokalemia results from an increased secretion of potassium from the body, abnormal loses, transcellular shifts, and insufficient intake. Insufficient intake of potassium is rarely a sole cause of hypokalemia but it contributes to the development of this disease. There are some medications that cause potassium loss which leads to hypokalemia and some medication include diuretics. Gastrointestinal loses are another common cause of hypokalemia. A gastrointestinal loss in the form of persistent diarrhea often results in potassium deficiency. Renal kidney dysfunction is also one of the causes of hypokalemia as due to dysfunction kidney may not function normally and excretes too much potassium. Plasma concentration also plays a major role in potassium excretion and when the lack of potassium occurs, the mechanism that retains potassium are inefficient as compares to the mechanism for sodium conversation. Even during the severe potassium depletion, urinary loss of potassium continues at the same rate. Also, if abnormal white blood cells are present in large number, they can take up extracellular potassium that results in a low potassium level.
Consequences associated with Hypokalemia
Deficiency of potassium throws a negative impact on the health of the body and it can alter the functioning of various organs. The most affected systems of the body include cardiovascular system, neurologic system, muscles, and kidneys.
1. Cardiovascular system
Hypokalemia has two major effects on the cardiovascular system, firstly it induces hypertension and secondly, it highly increases the risk of developing ventricular arrhythmias. Hypertension is a disease which is also known as high blood pressure and it is a condition in which the force of the blood against the walls of the artery becomes high. Many pieces of evidence reveal that a decrease in the amount of potassium can increase the blood pressure. Ventricular arrhythmias are abnormal heart rhythm and it occurs due to damage to the heart muscle. Hypokalemia leads to intravascular expansion due to renal retention.
2. Hormonal changes
Deficiency of potassium is known to impair insulin secretion, it impairs both insulin release and end-organ sensitivity to insulin and as a result, it leads to the development of diabetes mellitus and worsens the condition of diabetic patients. This impairment will lead to an increased blood glucose level in the body and it is also associated with other health complications.
3. Renal Cystic disease
Hypokalemia is highly associated with a condition in which the adrenal gland produces too much aldosterone and this further leads to the development of a renal cystic disease. This condition is characterized by the cyst that occurs in the duct epithelium and is associated with interstitial scarring.
4. Hepatic Encephalopathy
Hepatic encephalopathy is a health condition which is characterized as an alteration in the level of concentration due to the liver failure. Symptoms of hepatic encephalopathy include changes in personality, changes in mood and changes in movement. Various studies have suggested that hypokalemia or potassium deficiency increases the risk of developing hepatic encephalopathy or can worsen the symptoms of this disease. Ammonia is a toxin that causes hepatic encephalopathy and hypokalemia increases proximal tubule ammoniagenesis.
Hypokalemia also throws its negative impact on the muscular system and can result in several muscular related health problems. It can hyperpolarize skeletal muscle cells and impairs the ability to develop the depolarization which is necessary for muscle contraction.