Elevated potassium levels primarily affect a person's heart. When potassium builds up in the bloodstream, often because the kidneys aren't properly filtering it out, people may experience weakness accompanied by an irregular heartbeat and other symptoms. This condition, called hyperkalemia, can be detected by a medical professional if a patient exhibits symptoms. Prolonged elevated levels of potassium, or extreme overdoses of it, can be life threatening.
In some cases, a person whose potassium is high, but not excessively so, may not feel any symptoms. For others, symptoms may be simply unpleasant or attributed to some other cause. Tiredness and weakness, for example, might not be immediately linked as being effects of elevated potassium levels.
As levels rise and the situation worsens, however, additional effects like hyperventilating may occur as the body tries to deal with the extra potassium. When a person hyperventilates, he or she breathes more and more quickly than usual. This rapid breathing causes changes to the blood chemistry, and can also cause levels of potassium in the blood to drop.
The most common effects of elevated potassium levels are disruptions to the heart muscle. Potassium is an electrolyte, which is a chemical capable of conducting electricity. In the heart, this mineral helps regulate the heartbeat. Elevated levels of potassium, however, can cause heart palpitations and irregularities, and lead to a disrupted heartbeat called arrhythmia. Arrhythmia must be corrected as soon as possible, as it puts the patient at risk for sudden death. Very high levels of potassium can even cause the heart to stop.
As potassium helps with the transfer of electric impulses through the nerves, elevated levels can affect the nervous system, causing it to send inaccurate signals. This can cause a range of neurological systems, including muscle weakness and paralysis. Often, one of the first signs of elevated potassium is difficulty moving the digits or limbs as nerve signals are not transmitted correctly.
One common reason that an individual may have elevated potassium levels is a dysfunction of the kidneys. Usually, people keep very consistent levels of potassium thanks to the filtering action of the kidneys, and so anything that impedes this, like lupus or kidney stones, can result in elevated potassium levels. Conditions of the adrenal glands, such as Addison's disease, can also cause the condition. Acidosis caused by diabetes can raise the concentration of potassium in the blood, as can severe tissue damage resulting from burns, some other type of trauma, or any medical condition that destroys tissue cells.
It is often difficult to obtain accurate measurements of blood potassium levels as the sample can be "hemolyzed," where the pressure of drawing blood into a vial or syringe breaks open the walls of red blood cells. When this happens, the concentrated amounts of potassium found in the cells leaks into the plasma, giving false high potassium readings. For this reason, healthcare professionals will often request further evaluation using an electrocardiograph, or an ultrasound of the kidneys, before finalizing a diagnosis of hyperkalemia.
In the short term, severely elevated potassium levels are brought under control using one of several medications, such as insulin, sodium bicarbonate, or diuretics. Dialysis may be used if the kidneys are not working correctly. For the long term, patients must eliminate the use of potassium supplements, change any medications that might be exacerbating the problem, and adhere to dietary restrictions. Then, a healthcare professional will investigate and treat the underlying cause, depending upon what that is.