Blood potassium levels of 3.6 to 4.8 milliequivalents per liter, or mEq/L, are necessary for proper functioning of nerves and muscles. However, when blood levels of potassium rise higher than normal, into the range of 6.0 mEq/L, a condition called hyperkalemia occurs. Hyperkalemia is generally the result of an underlying disorder or extremely high levels of supplementation, since intake through food doesn't generally provide sufficient potassium to cause this problem.
Causes
Kidney diseases that hamper the removal of potassium from the bloodstream are a major cause of hyperkalemia. These disorders can include glomerulonephritis, acute or chronic kidney failure and obstructive uropathy. People with reduced kidney function may develop high blood potassium after tissue damage, such as a burn or surgery. Other causes include hormone disorders and some medications, such as certain diuretics. An overdose of potassium supplements can cause hyperkalemia, but developing high blood potassium from food alone is unlikely. Ingestion of 18g or more is typically needed to cause high blood potassium levels.
Symptoms and Complications
In most cases, people with high blood potassium levels exhibit few symptoms. Some people may feel nauseous or develop a slow, weak pulse. Tingling hands and feet and muscle weakness could also indicate high potassium. If blood potassium levels remain high for a long time, cardiac problems can develop, including an irregular heartbeat, heart arrhythmia and cardiac arrest. Some individuals may also experience a loss of neuromuscular control.
Treatment
In severe cases, emergency treatment may be necessary for hyperkalemia. Treatment includes hospitalization, which may involve dialysis or intravenous administration of calcium, glucose or insulin. Medications used to treat high blood potassium include diuretics that specifically target and remove potassium from the blood, cation-exchange resins and sodium bicarbonate. For long-term treatment, diuretics may be used and the individual will typically need to go on a low potassium diet.
Considerations
Because of the potential for hyperkalemia, people who are taking potassium supplements or who have kidney disease should have their blood tested on a regular basis for signs of high potassium. Individuals who are not at risk for hyperkalemia should not limit potassium in the diet and may want to increase intake to around 4,700mg per day, since this level has been linked to a lowered risk of osteoporosis, hypertension, stroke and kidney stones.
