Potassium is an electrolyte required for the normal functioning of cells. Most of your body's potassium is located inside of cells with levels of potassium in the blood tightly regulated by several mechanisms. High levels of potassium can result from many causes and lead to signs and symptoms including muscle weakness or cramping, cardiac arrhythmias and even death, The Merck Manuals Online Medical Library notes.
Kidney Failure
Kidney failure accounts for the largest proportion of cases of high potassium. Under normal conditions, the kidneys tightly regulate potassium levels to maintain a constant amount in the blood. In both chronic and acute renal failure, the decreased function of the kidney limits the amount of potassium that can be excreted leading to a buildup in the blood.
Acidosis
Acidosis, or a lowering of the pH of the body, can cause an exchange of hydrogen ions for potassium. Acidosis can result from respiratory or metabolic origins. Respiratory acidosis results from a decreased respiratory effort or rate, causing carbon dioxide to increase in the blood and lower the pH. Decreases in bicarbonate in the blood cause a metabolic acidosis. In cases of high potassium caused by acidosis, the total body potassium is not increased, according to MedlinePlus, a publication of the National Institutes of Health. Instead, the high levels result from the movement of potassium out of the cells as the excess hydrogen ions move into the cell. This shift leads to higher levels of potassium outside of the cells and in the blood.
Endocrine Dysfuntion
Aldosterone, released from the adrenal glands, regulates potassium secretion by the distal tubules in the kidney. Adrenal dysfunction or damage can result in altered levels of the hormone aldosterone and ultimately high potassium levels. Addison's disease results from damage to the adrenal cortex, the portion of the gland that secretes aldosterone. In Addison's disease, the decreased aldosterone levels lead to a decreased secretion of potassium and a subsequent increase in total body and blood levels, MedlinePlus notes.
Cell Injury
Injury to cells resulting from burns, muscle crush, traumatic injury, gastrointestinal bleeding and surgery causes the release of intracellular potassium into the surrounding interstitial fluid and blood. Conditions and disorders that cause the rupture of red blood cells, or hemolysis, can also increase potassium levels.
Drugs
Many drugs can cause high potassium levels. Certain types of diuretics, or drugs that increase urine output, and drugs that affect renal blood flow can decrease potassium excretion. According to MedlinePlus, potassium sparing diuretics such as spironolactone and epleranone cause retention of potassium by the kidneys and increase blood levels. Blood pressure medicines including angiotensin converting enzyme inhibitors and angiotensin receptor blockers can also cause high potassium levels, notes the Merck Manual.
Excess Intake
An excess intake of potassium can occur from potassium rich diets, excessive use of potassium supplements, blood transfusions and regular use of medications containing potassium, states the Merck Manual. Normally functioning kidneys will remove the extra potassium. However, small decreases in renal function may lead to high potassium levels when there is excess intake.
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