Typically, hypercalcemia causes include the use of calcium and vitamin D supplements, overactivity of the parathyroid glands, and certain medications, such as lithium. In addition, temporary hypercalcemia can be related to dehydration. Generally, when a person becomes dehydrated, there is less blood volume, resulting in higher levels of calcium concentration. This is a temporary condition, which often resolves itself when the person becomes re-hydrated, either by taking oral fluids, or by receiving intravenous fluids. Treatment for hypercalcemia is usually dependent upon the cause.
Sometimes, hypercalcemia causes can be related to cancer. Certain cancers, such as lung cancer, breast cancer, and certain blood cancers release proteins in the blood that simulate the actions of parathyroid hormones. This action can release calcium from the bones into the bloodstream. This condition is sometimes referred to as paraneoplastic syndrome, which is the body's response to substances that the cancer produces. In addition, metastasis, or spreading of a cancer to the bones can increase the risk of hypercalcemia.
Frequently, medications used to treat bipolar disorder can increase the release or presence of parathyroid hormone. This release can cause hypercalcemia, as can taking diuretics. Thiazide diuretics are "water pills" that are used to rid the body of excess water and lower blood pressure. Although these diuretics are effective in the treatment of edema and high blood pressure, they are one of the most common hypercalcemia causes. They can cause an increase blood calcium level by depleting calcium that is lost in the urine. Sometimes, when diuretic- induced hypercalcemia is severe, the physician may change medications to another type of diuretic.
Other diseases responsible for hypercalcemia may include tuberculosis and sarcoidosis. These diseases produce inflammation because of tissue injury. These tissue injuries are referred to as granulomas, which can elevate blood levels of calcitriol. Generally, increased calcitriol levels can cause the digestive system to absorb increased amounts of calcium, which may raise calcium levels in the blood. In addition, a genetic disorder called familial hypocalciuric hypercalcemia can cause a rise in blood calcium because calcium receptors in the body do not work effectively.
Generally, the presence of hypercalcemia can be detected by a simple blood test, however, actual hypercalcemia causes may be more challenging to diagnose. Typically, diagnosis of hypercalcemia causes will be based on the patient's complete medical history, including medications being taken and presence of certain diseases. Many times, mild hypercalcemia will be asymptomatic, however, severe hypercalcemia may cause fatigue, lethargy, and confusion.