Calcium plays an important role in the normal functioning of all cells, tissues and organ systems. Having an excess amount of calcium in the blood is called hypercalcemia. Dietary intake of calcium and vitamin D, sunlight exposure, age and physical activity all play a role in maintaining calcium balance. The skin, gastrointestinal tract, kidneys and parathyroid glands are organs that play a key role in calcium metabolism. A variety of medical conditions--from excessive intake of calcium and vitamin D to hyperparathyroidism and bone destruction by cancerous conditions such as multiple myeloma--can cause excessive calcium in the blood.
Hypercalcemia can be asymptomatic. Constipation, nausea, vomiting, abdominal pain and loss of appetite are early symptoms of hypercalcemia. Thirst and excessive urination are also symptoms of high calcium levels in the blood. Losses of water by the kidney, nausea and vomiting can lead to dehydration if water is not replaced orally or intravenously. Severe dehydration can lead to hypovolemia and low blood pressure. Low blood pressure can cause tissue damage due to inadequate blood flow.
Hypercalcemia can cause the brain to malfunction. Confusion, emotional disturbances, delirium, hallucinations and coma are some of the manifestations of brain dysfunction due to hypercalcemia. These symptoms should resolve with adequate hydration and restoration of serum calcium to normal levels.
Calcium is essential to normal cardiac functioning. Hypercalcemia can cause dangerous cardiac arrhythmia. Arrhythmia caused by hypercalcemia can be fatal. Arrhythmia can manifest as weakness, dizziness and loss of consciousness. The pulse may be weak or absent, and shortness of breath may also be present. If any of these symptoms occur, call 911.
Over time, hypercalcemia can cause development of kidney stones. This condition, also referred to nephrolithiasis can cause reversible kidney failure or permanent scarring of the kidney.
Hypercalcemia can also cause pancreatitis. Pancreatitis is inflammation of the pancreas. Symptoms of pancreatitis can vary from nausea, vomiting and abdominal pain to severe life-threatening problems such as hypovolemia, shock, accumulation of fluid in the abdomen and coma. Acute respiratory failure requiring ventilation support can also occur as a complication of pancreatitis.
Hypercalcemia caused by parathyroid adenoma can manifest as fatigue and weakness of proximal muscles that is clinically comparable to that seen in primary neuromuscular diseases. This condition is fully reversed after surgical removal of the parathyroid adenoma.
- Merck Manuals Online Medical Library: Calcium
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci, M.D., et al. (eds.); 2008