The University of Texas Medical Branch reports that hypercalcemia is the most common disorder associated with lung, neck, head and breast cancers. Doctors use the term hypercalcemia to describe high levels of calcium in the blood. Although the body needs calcium to function normally, an excessive amount of calcium in the bloodstream causes life-threatening consequences.
Significance
The body maintains a very narrow normal range of calcium in the blood. The National Institutes of Health reports that normal blood calcium levels range from 8.5 to 10.2 mg/dL (milligrams per deciliter). As calcium levels exceed the upper level of the normal range, signs and symptoms of hyperkalemia appear. Initial signs and symptoms of high calcium levels include stomach pain, vomiting, constipation, nausea, dry mouth, excessive thirst, fatigue, moodiness, confusion, lethargy and irritability. Without treatment, hypercalcemia causes extreme muscle weakness and may lead to cardiac arrhythmia or coma.
Identification
Doctors use a simple blood test to determine the amount of calcium in the blood. Your doctor may order the calcium blood test on its own or order the basic metabolic panel. In addition to checking calcium levels, the basic metabolic panel also determines the amounts of blood urea nitrogen (BUN), creatinine, sodium, chloride, potassium, carbon dioxide and glucose in the bloodstream.
Cause
In healthy people, the bones constantly go through periods of bone formation and the breakdown of bone cells. The Shands Cancer Center at the University of Florida estimates that 99 percent of the calcium in the body remains in the bones, while only 1 percent circulates in the bloodstream. During the breakdown of bone cells, the cells release calcium and other minerals. In people with bone cancer, tumors damage the bones by causing fractures and pain. After bone damage occurs, the bone cells break down and release more calcium than normal. This leads to increased levels of calcium in the blood.
Treatment
Doctors prescribe diuretics, Pamidronate and calcitonin to reduce the amount of calcium in the blood. They also encourage cancer patients with hypercalcemia to increase fluid intake and maintain normal physical activity. Regular blood tests determine the effectiveness of these treatments and ensure that the amount of calcium in the blood does not rise to a dangerous level.
Complementary Testing
Since bone cancer affects the amount of calcium in the bones, your doctor may order a bone density scan. This test, also known as bone densitometry, helps medical professionals determine the amount of bone loss that has occurred. During this test, a technician exposes the patient to ionizing radiation. This radiation produces pictures of the body. The Radiological Society of North America recommends that you stop taking calcium supplements at least 24 hours before the test to avoid altering the results.
References
- University of Texas Medical Branch: Facts About Hypercalcemia and Cancer
- National Institutes of Health: Calcium - Blood Test
- University of Florida Shands Cancer Center: Hypercalcemia
- Radiological Society of North America: Bone Density Scan
- American Association for Clinical Chemistry: Basic Metabolic Panel
