Hypokalemia and hyperkalemia both refer to imbalances of potassium in the bloodstream. A lower than normal amount of potassium is called hypokalemia, and a higher than normal amount is called hyperkalemia. Both conditions can be classified as mild or severe, depending on the degree of deviation from normal levels. The causes of these two conditions and the treatments for them differ, although the goal in treating both conditions is to normalize potassium levels.
A certain level of potassium in the body is necessary for healthy cell function, particularly muscle and nerve cells and heart function. This nutrient is obtained through food, and is mostly stored in the cells of the body with a small percentage carried in the blood. The kidneys remove excess potassium which is then excreted in urine. Disruptions in this system can lead to hypokalemia and hyperkalemia.
Kidney problems can cause both hypokalemia and hyperkalemia, but otherwise the causes of the two conditions differ. High potassium is usually caused by kidney disorders that reduce the ability of the kidneys to remove excess potassium. Cell damage caused by injury, surgery, or disease can cause many cells to release their potassium into the bloodstream at once, resulting in hyperkalemia. Heavy consumption of salt substitutes may also lead to high potassium.
Low potassium levels are most commonly caused by not consuming or absorbing enough nutrients. Eating disorders, malnutrition, illnesses, or taking certain medications can interfere with potassium consumption or absorption. Taking laxatives can also contribute to the problem. Kidney diseases that lead to too much potassium being excreted can also cause hypokalemia.
Severe or even life threatening consequences can arise from serious cases of both hypokalemia and hyperkalemia, including heart attacks. Many people with hypokalemia do not have any symptoms or only vague symptoms, but some people experience weakness, tiredness, fainting, muscle cramping, stomach cramps, constipation, or a change in the rhythm of the heart. Hyperkalemia is similar in that most people have few symptoms or have only vague symptoms like tiredness, but some people do get nauseous, have an irregular or slow heartbeat, or a weak pulse.
The treatment of hypokalemia is straightforward and entails giving the person potassium by mouth or intravenously, although any underlying conditions need to be treated or the person's potassium levels will drop again. Hyperkalemia is generally treated by reducing potassium consumption, but emergency treatment of severe hyperkalemia is more complex. The patient will be given medications to reduce potassium levels, as well as medications that combat the effects of too much potassium on the body, including intravenous calcium, insulin, and glucose.