Potassium is essential to many vital processes in the body. Potassium is involved in the proper functioning of nerve and muscle cells, digestion, metabolism and maintaining the balance of both electrical and chemical processes in the body. Potassium is especially important in cardiac function. Normal serum potassium levels range between 3.6 and 4.8 mEq/L. A high level of potassium in the blood is often indicative of an underlying kidney dysfunction.
High blood potassium, or hyperkalemia, often indicates that the body is producing too much potassium or that the kidneys can no longer remove excess potassium properly. Hyperkalemia can indicate kidney failure, infection, obstruction or even a transplant rejection. The hormone aldosterone regulates how the kidneys remove excess sodium and potassium. A lack of aldosterone can lead to an elevation of blood potassium, according to the National Institutes of Health. Anytime potassium releases from the cells it can raise potassium levels. A condition known as acidosis will move potassium from inside the cells to the fluid outside. Tissue injuries such as burns, traumatic injury, hemolytic conditions in which blood cells burst and muscle breakdown can all lead to acidosis and increased serum potassium.
A slight elevation in serum potassium will often not cause symptoms. However, when potassium increases, it causes disturbances in electrical functions of the body, interfering with the heart's ability to beat properly. The University of Maryland Medical Center explains that as potassium increases, people are likely to notice muscle aches and cramps, fatigue, weakness, difficulty breathing, irregular heartbeat, nausea, and weak or absent pulses. Elevated serum potassium can lead to life-threatening complications including paralysis, cardiac arrest and death.
Testing for an elevated serum potassium level involves a simple blood test performed in a lab, physician’s office or hospital. Commonly, the medical staff will run a panel of all electrolytes as well as test kidney and liver function. Elevated serum potassium does not necessarily mean that the kidneys are malfunctioning or that there is an underlying disease process at work. In some cases, an elevated blood potassium level can appear falsely elevated. Physicians will often retest if an error is suspected.
There are many reasons why a person’s potassium may appear elevated. Lab Tests Online explains that clenching and relaxing the fist repeatedly during collection of the sample can cause a false elevation. Improper testing of the blood by the lab can also lead to a false elevation, as can allowing the sample to sit at room temperature for too long prior to testing. Crying or rapid, shallow breathing can also lead to a false elevation.
If physicians confirm a diagnosis of hyperkalemia, treatment will involve not only treating the underlying condition but also balancing potassium levels. Calcium chloride or gluconate will help to minimize the effects of the excess potassium on the heart. Insulin, sodium bicarbonate and beta agonists will all help to promote the shift of potassium from blood to cells, according to the University of Maryland Medical Center. Diuretics can help promote excretion of excess calcium from the kidneys.