Hypercalcemia is a condition in which the calcium level in your blood is above normal. Too much calcium in your blood can weaken your bones, create kidney stones, and interfere with the way your heart and brain works.

Hypercalcemia most commonly results from overactive parathyroid glands. These four tiny glands are each about the size of a grain of rice and are located on or near the thyroid gland. Other causes of hypercalcemia include cancer, certain other medical disorders, some medications, and excessive use of calcium and vitamin D supplements.

Signs and symptoms of hypercalcemia may range from nonexistent to severe. Treatment depends on the underlying cause.

Symptoms Causes Risk factors Complications

You might not experience any signs or symptoms if your hypercalcemia is mild. More-severe cases produce symptoms related to the parts of your body affected by the high calcium levels in your blood. Examples include:

  • Kidneys. Excess calcium in your blood means your kidneys have to work harder to filter it out. This can cause excessive thirst and frequent urination.
  • Digestive system. Hypercalcemia can cause stomach upset, nausea, vomiting and constipation.
  • Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain. Some people who have hypercalcemia also experience muscle weakness.
  • Brain. Hypercalcemia can interfere with the way your brain works, resulting in confusion, lethargy and fatigue.

When to see a doctor

Contact your doctor if you develop signs and symptoms that may indicate hypercalcemia — such as being extremely thirsty, urinating frequently and having abdominal pain.

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