Final answer:
Hyperparathyroidism, caused by a parathyroid tumor, leads to excessive secretion of parathyroid hormone, resulting in weakened bones, possible fractures, hypercalcemia, and nervous system issues. High blood calcium can also cause calcification in other body tissues and organs, leading to various health complications.
Step-by-step explanation:
A tumor of the parathyroid gland often results in the secretion of excess parathyroid hormone (PTH), a condition known as hyperparathyroidism. PTH plays a crucial role in regulating blood calcium levels by increasing calcium reabsorption in the kidneys, stimulating osteoclast activity to release calcium from bones, and enhancing calcium absorption in the digestive system through the synthesis of calcitriol. Excess PTH leads to excessive calcium removal from bones and release into the bloodstream, which can cause bone weakness, deformities, fractures, and nervous system impairment due to high blood calcium levels, also known as hypercalcemia.
In severe cases, high levels of calcium in the blood can result in the deposition of calcium in body tissues and organs, interfering with their normal function. Hyperparathyroidism can lead to bone diseases such as osteoporosis and may also result in kidney stones due to the increased levels of calcium in the urine. Conversely, inadequate production of PTH, or hypoparathyroidism, results in too little calcium in the blood, which can impair muscle function and potentially cause tetany.