Potassium is a mineral that helps maintain the water and acid balance in blood and tissue cells, assists in muscle building, and transmits electrical signals between cells and nerves. Symptoms of hypokalemia, or potassium deficiency, include dry skin, muscle weakness, fatigue, and slow reflexes. If the deficiency develops rapidly or is left unchecked, heart problems and paralysis may result. Hypokalemia is a very serious condition which requires immediate medical attention.
Effects on Blood Pressure, Skin, and Bones
When a person suffers from a mild potassium deficiency, he or she may not have any symptoms. People with low potassium can develop a sensitivity to salt or sodium, however, which can lead to high blood pressure. Abnormally dry skin can also be caused by low potassium, as the mineral plays an important role in maintaining fluid levels in cells. Potassium is also necessary for bone health, as it prevents the alkaline compounds found in bones from being used up by the body's natural metabolic acids; low potassium is associated with an increased risk for osteoporosis.
Fatigue, Irritability, and Confusion
People with potassium deficiency may also feel tired and weak. The mineral helps the body to use glucose, its main source of energy, so when this process isn't working correctly, it can leave a person feeling run down. In addition to fatigue, when the muscles don't have enough energy to work correctly, they can become weak and achy.
As an electrolyte, potassium plays a key role in the movement of electrical impulses throughout the body. When a person has low potassium, those impulses may slow down or not travel as they should. This may lead to irritability, anxiety, confusion, and depression, which may only worsen when combined with other effects, like tiredness and weakness.
Potassium plays a key role in muscle contraction, so a deficiency of this mineral can cause a range of muscular symptoms. Slow reflexes, cramps, twitches, and spasms are all effects of potassium deficiency. Problems with the legs during sleep, including restless leg syndrome and charley horses — strong, sudden cramps in the calf muscles — may also be worse in people who do not get enough of this mineral.
Over time, a severe potassium deficiency can even cause damage to the muscles themselves, causing the fibers to break down. This can lead to rhabdomyolysis, a condition in which proteins from the muscle fiber are released into the bloodstream. These proteins can damage the kidneys and, in serious cases, cause kidney failure.
Paralysis and Digestive System Problems
Low potassium can also result in paralysis, as the mineral is essential for the transport of electrical signals that allow muscle movement. Paralysis can occur in any part of the body, but is particularly associated with the digestive system. When parts of this system become paralyzed, food cannot be digested properly, leading to stomach and intestinal cramps, constipation, and bloating.
Thyrotoxic periodic paralysis can also occur, which is caused by an excess of thyroid hormone in the body. Treating this excess of the thyroid hormone raises the levels of potassium in the body, which should improve the muscle weakness and paralysis. Another type of paralysis, hypokalemic periodic paralysis, is a congenital condition caused by low potassium levels. In these cases, the potassium deficiency is not caused by illness or diet, but is due to an abnormal transfer of potassium between blood and muscle cells.
One of the most dangerous effects of a potassium deficiency is that it can cause the heart to beat abnormally, called dysrhythmia. A person with dysrhythmia may experience a sudden fast heartbeat, chest pain, and dizziness. This is a potentially life threatening condition, as it can cause cardiac arrest and cause the heart to stop beating completely.
Known causes of hypokalemia include excessive diarrhea, sweating, and vomiting. Using diuretics and laxatives, as well as eating disorders such as bulimia, may cause a magnesium deficiency, which may be a contributing factor to developing this condition. Some antibiotics and other medications can cause this condition as well. Diseases that inhibit the kidney's potassium retention capabilities, such as Liddle syndrome, hyperaldosteronism, and Cushing syndrome, all can cause a potassium deficiency, as can hyperthyroidism, an illness that causes the thyroid to produce too much hormone.
When potassium deficiency can be attributed to a specific disease or vomiting and diarrhea, a health care professional can usually treat the underlying conditions, and ensure that there is sufficient potassium in the diet. If medication is the cause, a change in prescription may be possible in some cases, or a high potassium diet may be recommended. Mineral supplements may also be necessary if the patient cannot get enough potassium through diet alone. In severe cases, potassium may be administered intraveneously.
Foods that are high in potassium include beef, chicken, and fish such as cod, salmon, and sardines. Good vegetable sources include peas, tomatoes, leafy greens, lima beans and potato skins. Bananas, seaweed, melons, apricots, and citrus fruits are also rich in potassium. Dried fruits such as mangoes and apricots provide concentrated sources of potassium, as do nuts and chocolate.