Hyperkalemia (cont.)
Diseases of the adrenal gland
Adrenal glands are small glands located adjacent to the kidneys, and are
important in secreting hormones such as cortisol and aldosterone. Aldosterone
causes the kidneys to retain sodium and fluid while excreting potassium in the
urine. Therefore diseases of the adrenal gland, such as Addison's disease, that lead to decreased
aldosterone secretion can decrease kidney excretion of potassium, resulting in
body retention of potassium, and hence hyperkalemia.
Potassium shifts
Potassium can move out of and into cells. Our total body
potassium stores are approximately 50 mEq/kg of body weight. At any given time,
about 98% of the total potassium in the body is located inside of cells
(intracellular), with only 2% located outside of cells (in the blood circulation
and in the "extracellular" tissue). The blood tests for measurement of potassium levels
measure only the potassium that is outside of the cells. Therefore, conditions
that can cause potassium to move out of the cells into the blood circulation can
increase the blood potassium levels even though the total amount of potassium in
the body has not changed.
One example of potassium shift causing hyperkalemia is diabetic ketoacidosis.
Insulin is vital to patients with
type 1 diabetes.
Without insulin, patients with type 1 diabetes can develop severely elevated blood glucose levels.
Lack of insulin also causes the breakdown of fat cells, with the release of ketones into
the blood, turning the blood acidic (hence the term ketoacidosis). The acidosis
and high glucose levels in the blood work together to cause fluid and potassium
to move out of the cells into the blood circulation. Patients with diabetes
often also have diminished kidney capacity to excrete potassium into urine. The
combination of potassium shift out of cells and diminished urine potassium
excretion causes hyperkalemia.
Another cause of hyperkalemia is tissue destruction, dying cells release potassium into the blood circulation. Examples of tissue
destruction causing hyperkalemia include:
Next: Medications »
- ACE Inhibitors - Read about ACE inhibitors like Altace, lisinopril, enalapril, ramparil, Zestril and more. Information includes side effects, drug interactions, and pregnancy safety information.
- Electrolytes - Read about blood electrolytes (sodium, potassium, chloride, and bicorbonate) and the effects of electrolyte imbalances like kidney failure, low blood pressure, hypokalemia, and hyperkalemia.
- Kidney Failure - Learn about kidney failure, in which the body has fluid retention, risen blood pressure, toxin build up and lack of red blood cells. Symptoms include fatigue, nausea, and apetite loss.
Latest Medical News
Interactive Slideshows