Low levels of potassium in the blood results in a serious condition called hypokalemia. In this disorder, the normal functioning of the heart and muscles is altered. Adrenal gland diseases can cause hypokalemia because aldosterone--a hormone produced by the adrenal glands--determines how much potassium is present in the body.
Potassium is mostly found inside the body's cells. This fact is important because it helps maintain membrane potential--a term used to describe concentration of potassium within and outside cells. Membrane potential drives many functions of potassium, such as transferring nerve impulses and maintaining heart function. Potassium also regulates smooth muscle and skeletal muscle contractions due to membrane potential. Additionally, it must be present for certain enzymes to work.
Hyperaldosteronism involves the presence of higher-than-normal levels of aldosterone in the body. Aldosterone maintains water balance in the body and blood pressure. It causes the kidneys to secrete more potassium and less sodium. Therefore, an imbalance in this hormone disrupts blood levels of potassium. In this disease, high blood levels of aldosterone stimulate the kidneys to excrete more potassium than usual, and this can lead to hyperkalemia, or high potassium in the blood.
The Columbia University Medical Center reports that a benign tumor in the adrenal glands can cause hyperaldosteronism. Enlarged adrenal glands--also referred to as bilateral adrenal hyperplasia--can also cause hyperaldosteronism.
The electrical system of the heart ensures that the heart beats in a regular fashion, so that blood moves through the heart and body properly. Potassium is necessary for this heart function and when it is deficient, the Mayo Foundation for Medical Education and Research reports that irregular heartbeats or abnormal heart rhythms occur. Weakness, muscle cramps and fatigue are symptoms of hypokalemia. Hypokalemia can cause weakness in the smooth muscles of the digestive tract, and this can cause constipation, abdominal pain and bloating.
The Merck Manuals Online Medical Library explains that treatment for hypokalemia involves treating its underlying cause. If a disorder such as hyperadlosteronism is the causative factor, then surgery or medications may be used to treat it. Hyperaldosteronism caused by adrenal tumors is treated by surgically removing the tumors. Medications such as eplerenone or spinorolactone are used to treat hyperaldosteronism caused by enlarged adrenal glands. They block the action of aldosterone.