Potassium is one of the most essential minerals required by the human body, and is crucial for the normal functioning of muscle cells and nerves. It is predominantly present inside the cells as a positively charged ion (K⁺) or in the form of potassium chloride (KCl). Potassium plays an important role in maintaining normal cellular functions and metabolism. It also helps to maintain each cell's electrical potential and electrolyte balance as well as the acid-base balance in the body fluids. Potassium is necessary for the efficient functioning of both voluntary and involuntary muscles. It also contributes to the transmission of nerve impulses, muscle contraction, and regulation of heartbeat. Potassium is important for digestive health as well as the normal functioning of the heart and kidneys. The normal level of potassium in the serum is 3.5-5.0 mEq/L, and alterations in these levels can interfere with several body functions. A reduced level of serum potassium is known as hypokalemia, while a condition characterized by high potassium levels is referred to as hyperkalemia. Given below is brief account of the diseases or conditions that may cause a reduction in the levels of potassium in blood. Hypokalemia or low potassium, is characterized by muscle weakness and muscle paralysis. One out of five people is diagnosed with hypokalemia in the United States alone. Dietary deficiency of potassium is one of the obvious causes for hypokalemia, but is rarely observed since this mineral is abundantly present in several fruits and vegetables that are consumed daily. The major factor responsible for low levels of potassium is the excessive loss of potassium from the body. Such a loss may occur due to the following reasons. Certain kidney diseases and conditions such as acute renal failure, chronic kidney disease (CKD), and renal tubular acidosis can cause low potassium levels. These conditions are characterized by inefficient excretory functions leading to excessive loss of potassium from the body through urine, as well as due to vomiting and diarrhea. In addition, conditions like Bartter syndrome and Fanconi syndrome, that are characterized by altered nephron function, may also be responsible for hypokalemia. The action of certain hormones like insulin and aldosterone is responsible for maintaining the optimum levels of potassium in the body. An imbalance in these hormones may lead to excessive loss of potassium from the body. The major hormonal problems that affect potassium levels are: ► Primary aldosteronism: It is characterized by an overproduction of the hormone aldosterone by the adrenal glands. This leads to loss of potassium and excessive retention of sodium by the kidneys. ► Diabetic ketoacidosis: This condition is a result of excessive utilization of the fat reserves in individuals suffering from type 1 diabetes. It leads to formation of ketones, disruption of the acid-base balance of urine, as well as frequent urination, which ultimately leads to hypokalemia. In rare cases, it can also be found in case of type 2 diabetes. ► Cushing's syndrome: It is characterized by an increase in the production of cortisol which leads to loss of potassium ions and retention of sodium ions. Certain health conditions such as diarrhea or vomiting can lead to excess loss of potassium. Enemas or excessive use of laxatives can also cause hypokalemia. Significant hypokalemia can occur in people who have undergone ileostomy or other bowel surgeries. Villous adenoma is a type of colon polyp, which can cause the excessive excretion of potassium from the colon. Low potassium levels may arise as a side effect of certain medications such as diuretics (water pills), laxatives, insulin, prednisone, amphotericin B, and aminoglycosides, such as tobramycin or gentamicin. Medications used for emphysema or asthma such as steroids, bronchodilators, or theophylline may also lead to low levels of potassium. Some of the common symptoms of potassium deficiency are:

• Fatigue
• Hypertension
• Heart problems
• Improper digestion
• Retarded bone growth

Apart from the above-mentioned causes, disruption in the balance between intracellular and extracellular potassium content, resulting in abnormal shifting of potassium inside the cells, can lower the levels of serum potassium. A very low potassium level (below 2.5 mEq/L) can be life threatening, and needs immediate medical treatment. Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a substitute for professional medical advice.