Hypercalcemia
M. Gina Glazier and Judith A. Fisher
The normal concentration of calcium in the extracellular fluid is 8.5 to 10.5 mg/dl. Symptoms usually occur when the calcium level rises to 12.5 mg/dl or above. Serum calcium levels between 10.5 and 12 mg/dl are usually asymptomatic.
Approach
A. Manifestations. Although most patients with hypercalcemia are asymptomatic (1), patients with symptomatic hypercalcemia can have a variety of vague complaints: generalized muscle weakness, muscle aches or pains, incoordination, change in level of consciousness, headache, loss of appetite, nausea, vomiting, constipation, increased salivation, dysphagia, severe abdominal pain, abdominal distension, or itching. These patients may present with a renal calculus or a history of a renal calculus. Physical examination may reveal mental confusion, poor memory, slurred speech, acute psychotic behavior, lethargy or coma, ataxia, poor over-all muscle strength, hypotonia, hyperextensible joints, increased deep tendon reflexes, positive Babinski’s sign, incoordination, loss of pain or vibration sense, calcium deposits on the conjunctiva near the palpebral fissure or on the cornea around the iris, an acute abdomen, or an ileus. Patients with hypercalcemia can also present with another diagnosis such as malignancy. In malignancy, hypercalcemia is often a sequitor. A calcium level should be ordered only if hypercalcemia is suspected after the history and physical examination.
It is important to note that calcium levels are frequently ordered to investigate nonspecific symptoms and mild, asymptomatic hypercalcemia is a frequent incidental finding. In dehydration with hemoconcentration, serum calcium can be falsely elevated. If this is the case, a second blood sample should be drawn after the hemoconcentration has resolved.
B. Common causes. Of the cases of hypercalcemia in adults, 90% are caused by hyperparathyroidism or malignancy. Hyperparathyroidism is the most common outpatient cause of hypercalcemia. In primary hyperparathyroidism, the serum calcium is less than 14.5 mg/dl, with serum chloride more than 102 mEq/L in the setting of a normal alkaline phosphatase, increased parathyroid hormone level (PTH), and no clinical evidence of malignancy.
Malignancy is the most common cause of hypercalcemia in hospitalized patients (2–3). Hypercalcemia secondary to malignancy occurs through metastatic involvement of bone, or the tumor itself may secrete a parathyroid
hormone-related-protein that causes bone resorption. In multiple myeloma, hypercalcemia is caused primarily by impairment of glomerular filtration and subsequent renal failure. Patients with malignancy and hypercalcemia have higher calcium levels that are less amenable to treatment. Most of these patients will die within 3 to 6 months. In hypercalcemia associated with malignancy, the serum calcium is 14 mg/dl or higher, with a serum chloride less than 100 in the setting of anemia, a serum alkaline phosphatase of more than two times the upper limit of normal, and a normal or less than twice the upper limit of normal PTH.
The less common causes of hypercalcemia (e.g., renal failure and hyperthyroidism) can be ruled out with normal renal and thyroid functions (Chapters 10.5 and 14.8). Sarcoidosis can be ruled out with a normal chest x-ray study.
C. Special concerns. Symptomatic hypercalcemia with levels above 12.5 mg/dl can be a life-threatening metabolic emergency. It is important to order an electrocardiogram and begin treatment immediately, as cardiac arrest, convulsions, or coma can occur. Further testing can be done while the serum calcium is being lowered (Table 17.4).
References
1. Bushinsky DA, Monk RD. Calcium. Lancet 1998;352:306–311.
2. Al Zahrani A, Levine MA. Primary hyperparathyroidism. Lancet 1997;349:1233–1238.
3. Mundy GR, Guise TA. Hypercalcemia of malignancy. Am J Med 1997;103:134–145.
Pictures
Book Source Details
- Book Title: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter
- Author(s): Robert B. Taylor (editor)
- Year of Publication: 2000
- Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2000 Lippincott Williams & Wilkins.
Other Book Chapters Related to Hypercalcemia
Read excerpts from these other book chapters related to Hypercalcemia:
Medical Books Excerpts
- Hypercalcemia
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
Copyright Details: The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter, Copyright © 2008 Williams & Wilkins.
More About Causes of Hypercalcemia
» Next page:
Aminotransferase Levels, Elevated (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
