The adrenals are a pair of glands that sit on top of each kidney. They secrete steroid hormones that regulate inflammation, and mineralocorticoids, which are hormones that control fluid balance and salts. Salts are composed of electrolytes, the electrically charged molecules that are important in muscle movement and the signals from the brain and the nervous system. Disorders of the adrenal glands can affect the overall levels of salts and electrolytes in the body.
Causes
According to the Merck Manual, the most common conditions that affect the adrenal glands are Addison's disease, in which the adrenal cortex fails to produce enough mineralocorticoid and steroid hormones, and primary aldosteronism, in which the adrenal gland produces excess amounts of aldosterone, the primary mineralocorticoid hormone that controls sodium and potassium levels. Other conditions that can cause salt imbalance include secondary aldosteronism, in which the adrenal produces too much aldosterone due to low blood flow to the gland or dehydration, and secondary adrenal insufficiency, in which the brain fails to stimulate enough production of these hormones.
Electrolyte Abnormalities
Aldosterone, the main hormone secreted by the adrenal cortex, stimulates the absorption of sodium from the kidneys and the excretion of potassium into the urine. Sodium and potassium are important salts that contribute to the body's fluid balance. A low-functioning adrenal gland, with low production of aldosterone, results in low sodium and high potassium in the bloodstream. Secretion of high levels of aldosterone, as in primary aldosteronism, results in high sodium and low potassium levels.
Sodium Abnormalities
High sodium, or hypernatremia, can cause nonspecific symptoms of nausea and vomiting, coupled with thirst, as the body tries to compensate for the increased salt by increasing the consumption of fluids. Confusion, lethargy and seizures can result as fluid leaves the brain and enters the bloodstream, where the level of sodium is higher, resulting in brain shrinkage. According to the Mayo Clinic, low sodium, or hyponatremia, can cause similar symptoms as hypernatremia, as well as muscle cramps and weakness, loss of appetite and fatigue.
Potassium Abnormalities
High potassium, also known as hyperkalemia, is a potentially dangerous condition. Potassium is important in maintaining a normal heart rhythm. High potassium levels can predispose to life-threatening arrhythmias, or abnormal heart rhythms. In particular, hyperkalemia can cause ventricular fibrillation, an abnormal quivering of the heart that impairs its ability to pump blood to the body. Low potassium, or hypokalemia, can cause muscle cramps, constipation and fatigue.
