Diagnosing Hypercalcemia in Older Adults: Key Steps and Underlying Causes

Hypercalcemia, or elevated calcium levels in the blood, is a relatively common metabolic issue among older adults. Accurate diagnosis is crucial because high calcium can signal underlying health conditions ranging from benign hormonal imbalances to life-threatening cancers. Identifying the root cause early improves outcomes and guides appropriate treatment.

Initial Blood Testing and Electrolyte Evaluation

The first step in diagnosing hypercalcemia involves a comprehensive blood test to measure serum calcium and other key electrolytes. If initial results show elevated calcium levels, further testing is necessary to confirm whether the hypercalcemia is persistent or transient. Since calcium metabolism is closely tied to parathyroid function, doctors typically assess parathyroid hormone (PTH) levels as part of the diagnostic workup.

The Role of the Parathyroid Glands

The parathyroid glands play a central role in regulating calcium and phosphorus balance in the body. When PTH levels are inappropriately high alongside elevated calcium, primary hyperparathyroidism is often suspected—a condition more prevalent in seniors. In rare cases, parathyroid cancer can also lead to excessive calcium release into the bloodstream. Imaging studies such as neck ultrasound or sestamibi scans may be used to evaluate the glands for adenomas or malignancies.

Differentiating Benign Causes from Serious Conditions

If parathyroid function appears normal and calcium elevation is mild, clinicians may explore non-pathological factors. Excessive dietary calcium intake or overuse of calcium supplements—especially without adequate vitamin D or physical activity to support bone deposition—can contribute to temporary increases in blood calcium. Reviewing medication history, supplement use, and recent dietary changes is an essential part of the evaluation.

Screening for Malignancy: A Critical Consideration in Seniors

In older patients, hypercalcemia should raise red flags for potential malignancy. Certain cancers produce substances that mimic parathyroid hormone, known as PTH-related peptide (PTHrP), leading to what's called humoral hypercalcemia of malignancy. This is particularly associated with lung cancer, breast cancer, and some types of lymphoma.

Common Cancer Types Linked to Elevated Calcium

Squamous cell carcinoma of the lung and certain adenocarcinomas are among the tumors most frequently responsible for cancer-induced hypercalcemia. These tumors can disrupt normal bone turnover by stimulating osteoclast activity, resulting in the release of stored calcium into the bloodstream. Early detection through imaging (such as CT scans or PET scans) and tumor marker testing can be lifesaving.

In summary, diagnosing hypercalcemia in the elderly requires a systematic approach that includes laboratory testing, assessment of parathyroid function, review of lifestyle and medication factors, and vigilant screening for underlying cancer. Timely and thorough evaluation ensures that seniors receive targeted care tailored to their specific condition.