In which condition would you expect to see high levels of parathyroid hormone (PTH)?

In cases of hyperparathyroidism, you would expect to see elevated levels of parathyroid hormone (PTH) due to the overactivity of the parathyroid glands. This condition occurs when one or more of the parathyroid glands become enlarged and produce excessive amounts of PTH, leading to hypercalcemia (high levels of calcium in the blood). PTH is crucial for regulating calcium levels within the body; it increases calcium reabsorption in the kidneys, mobilizes calcium from bones, and enhances intestinal absorption of calcium.

The presence of high PTH levels in hyperparathyroidism can result in various symptoms, such as kidney stones, bone pain, fatigue, and cognitive disturbances. This increase in PTH is a hallmark of the condition, distinguishing it from other disorders where the regulation of PTH is not similarly affected.

In contrast, conditions like hypoparathyroidism are characterized by low PTH levels, while thyroiditis and Cushing's syndrome are unrelated to the regulation of PTH directly and often involve other hormonal imbalances.