Hypocalcemia Differential Diagnosis

According to the Mayo Clinic hypercalcemia is a condition in which the calcium level in your blood is above normal. While some calcium is necessary for bone formation, excessive levels can upset the normal release of hormones and proper brain and nerve functions. The National Institutes of Health (NIH) say the differential diagnosis of hypercalcemia has grown to more than two dozen separate conditions. However, by differentiating that primary hyperparathyroidism and cancer account for up to 90 percent of all hypercalcemic patients, optimal treatment can be achieved by focusing on these two areas. All causes are looked at in differential diagnosis, with the most prevalent first.

Hyperparathyroidism and Cancer

• The primary cause of hypercalcemia is activity in at least one of your four parathyroid glands that is above what is normal (primary hyperparathyroidism). These glands control calcium. Post-menopausal women are prone to developing hypercalcemia due to overactive parathyroid glands.

  Certain types of cancer, especially lung cancer and breast cancer, can increase your chances of developing hypercalcemia. Some malignancies create a protein that mimics the parathyroid hormone, encouraging the release of calcium from your bones into your blood.

Other Causes

• Some diseases (tuberculosis, an infectious lung disease, and sarcoidosis, an inflammatory disease) may result in hypercalcemia. These conditions cause areas of inflammation due to tissue injury (granulomas) and may lead to excessive levels of vitamin D that in turn cause hypercalcemia.

  Certain medications such as lithium may increase the release of parathyroid hormone and cause hypercalcemia. Thiazide diuretics can result in high calcium levels in your blood by lowering the amount of calcium eliminated in your urine.

  Taking mega doses of calcium or vitamin D supplements over an extended period of time lead to above-normal calcium levels in your blood.

Symptoms

• Sometimes there are few if any signs to indicate hypercalcemia, while in other cases effects may be obvious and severe. Symptoms can include constipation, confusion, frequent urination and excessive thirst.

  Other signs of hypercalcemia include muscle pain and weakness, fatigue and abdominal pain.

Diagnosis

• A differential diagnosis of hypocalcemia includes gathering a personal and family medical history, compiling a list of symptoms and performing examinations and tests including a chest X-ray, computerized tomography (CT) scan, magnetic resonance imaging (MRI) scan and mammograms. These diagnostic tools may help identify whether lung cancer, breast cancer, other malignancies or diseases are present. A differential diagnosis is in essence a process of elimination, with the most likely causes tested for first.

Treatment

• The treatment of hypercalcemia may vary depending on how high the calcium level and why it is elevated. The drug furosemide, perhaps better known as Lasix, inhibits calcium reabsorption in the kidneys and encourages urine output.

  Phosphate pills reduce high calcium levels that are caused by a phosphate deficiency. Anti-inflammatory agents such as steroids are helpful with some cancers and toxic levels of vitamin D.

  Hyperparathyroidism is typically remedied by surgical removal of one or more of the parathyroid glands and any tissue that is producing an excess supply of the hormone.