A high level of calcium in the blood, a condition called hypercalcemia, causes nausea and vomiting, frequent urination, excessive thirst and constipation, notes Mayo Clinic. Bone pain, muscle weakness, confusion and fatigue are also potential effects of having too much calcium in the blood.
Because hypercalcemia is often diagnosed in its early stages, many people do not have any symptoms, reports MedlinePlus. When symptoms occur, they typically affect the digestive system, kidneys, bones and muscles. Hypercalcemia also causes psychological symptoms such as irritability, dementia, memory loss and depression.
Left untreated, hypercalcemia has serious effects on the body. Osteoporosis sometimes develops when the bones release too much calcium in the blood, explains Mayo Clinic. If there is too much calcium in the urine, there is an increased risk of developing kidney stones. Severe hypercalcemia also increases the risk for kidney failure, coma and irregular heartbeat.
Vitamin D and parathyroid hormone help regulate the amount of calcium in the blood, according to MedlinePlus. The most common cause of hypercalcemia is primary hyperparathyroidism, a condition characterized by the release of excessive amounts of parathyroid hormone from the parathyroid glands. In people with familial hypocalciuric hypercalcemia, a genetic disorder, the body is unable to regulate its calcium level properly. Kidney failure, hyperthyroidism, milk-alkali syndrome and some cancerous tumors also cause hypercalcemia.