Hypercalcemia describes a condition where the calcium level in the blood becomes too high. Calcium is a mineral important for many bodily functions, including nerve communication, muscle contraction, blood clotting, and heart rhythm. While most of the body’s calcium resides in bones, the small amount circulating in the blood is precisely regulated. When blood calcium levels rise above the normal range, it can disrupt these functions and potentially lead to health complications affecting bones, kidneys, the heart, and the brain.
The Primary Condition
The condition most frequently associated with hypercalcemia is primary hyperparathyroidism. This occurs when one or more of the parathyroid glands become overactive. These glands, typically four in number and located in the neck behind the thyroid, produce an excess of parathyroid hormone (PTH). Primary hyperparathyroidism accounts for a significant majority of hypercalcemia cases in outpatient settings. The overactivity often stems from a benign growth on one of the glands or an enlargement of the glands themselves.
How Parathyroid Glands Impact Calcium
The parathyroid glands play a central role in maintaining calcium levels within the blood. They release parathyroid hormone (PTH) in response to drops in blood calcium. PTH signals bones to release calcium into the bloodstream, prompts the kidneys to reabsorb more calcium instead of excreting it, and encourages the kidneys to produce active vitamin D, which in turn helps the intestines absorb more calcium from food.
In primary hyperparathyroidism, the parathyroid glands produce too much PTH regardless of the blood calcium level. This excessive PTH leads to persistently high blood calcium. Over time, this imbalance can manifest in symptoms such as fatigue, increased thirst, frequent urination, muscle weakness, joint pain, constipation, nausea, memory issues, and depression. Persistent high calcium can also lead to serious complications like kidney stones or weakened bones.
Identifying and Addressing the Condition
Diagnosing primary hyperparathyroidism involves blood tests measuring calcium and parathyroid hormone levels. A high blood calcium level with an elevated or inappropriately normal PTH level suggests the condition. Healthcare providers may also assess vitamin D levels and kidney function. Imaging tests like a sestamibi scan or ultrasound can pinpoint overactive glands.
Treatment varies based on severity and symptoms. For mild cases without significant symptoms, a “watchful waiting” approach may be recommended, involving regular monitoring of blood calcium, kidney function, and bone density. For symptomatic individuals, surgical removal of the overactive gland(s) is often the most effective treatment. Medications like calcimimetics can also be prescribed to help lower calcium and PTH levels. Consulting a healthcare professional for a thorough evaluation is important for anyone experiencing symptoms of hypercalcemia.