Every person has four parathyroid glands. The main function of these glands is to control the levels of calcium and phosphate in the body with the help of the parathyroid hormone (parathyroid hormone). Both calcium and phosphate are crucial factors in bone formation.
However, calcium also plays a very important role in nerve tissue and muscles. Day and night, the parathyroid glands measure the level of calcium in the blood. If this drops too low, the parathyroid hormone causes more calcium to be released from the bone stores.
If the parathyroid glands are overactive (= hyperparathyroidism), too much parathyroid hormone is released even if the calcium level in the blood is correct. The calcium is released from the bone, resulting in osteoporosis. As there is permanently more calcium in the blood than the body needs, more calcium is excreted. Kidney stones develop.
Schematic drawing of bones and kidneys. Courtesy of Dr. Georg Wille, MD.
In hyperparathyroidism, there is a benign proliferation of parathyroid cells, so that the parathyroid gland enlarges (usually to a diameter of approx. 1 cm). These so-called parathyroid adenomas also produce too much parathyroid hormone and flood the body with it. An adenoma produces far more than it needs (small uncontrolled hormone factory).
Parathyroid preparation. Courtesy of Dr. Georg Wille, MD.
Very often (approx. 80 %) such adenomas only affect one of the four parathyroid glands. According to statistics, two or more affected glands are found in about 20% of patients. It is extremely rare for a malignant tumor to cause hyperparathyroidism.
As a result of the disturbed calcium-phosphate balance, hyperparathyroidism leads to changes in the bone substance. The bones lose calcium and therefore stability. Doctors also call this "bone softening" osteoporosis.
Joint and bone pain are just as common. Musculoskeletal pain caused by primary hyperparathyroidism is often misjudged as an unclear complaint because no disease is detected. The diagnosis of polymyalgia rheumatica is therefore often made out of embarrassment. The key to a correct diagnosis would be a measurement of calcium and parathyroid hormone in the blood (in the same blood sample).
As the disease progresses, the disturbed calcium-phosphate balance also increasingly leads to kidney stones. Calcium phosphate deposits are often found in the small vessels, especially in the kidneys, which leads to kidney dysfunction over a long period of time.
Typical symptoms include elusive symptoms such as fatigue, loss of performance and a greater tendency to depression. High blood pressure, constipation and cardiac arrhythmia can also occur frequently.
Early detection of hyperparathyroidism is essential in order to avoid or at least limit long-term damage. Unfortunately, the disease is often only discovered during routine blood tests. These often only reveal a slightly elevated calcium level.
If your family doctor tells you that your calcium is a little too high - then ask for your parathyroid hormone (PTH) level to be determined . If this value is also elevated, there is a clear hyperfunction of the parathyroid glands.
Scintigraphy and ultrasound examinations are suitable imaging procedures for localizing the hyperfunctioning parathyroid gland.
In primary hyperparathyroidism, the causative adenoma must be surgically removed as part of parathyroid surgery. This operation is minimally invasive and is very well tolerated by patients. As not all parathyroid glands are usually equally affected, the remaining parts of the gland take over the important control function in the body's calcium balance.
If surgery is not possible, or to bridge the gap until the actual operation date, the patient can be treated with medication such as calcimimetics. Other medications reduce the calcium content in the blood and ensure that more calcium is stored in the bone tissue.
Increased fluid intake or infusions can also prevent kidney stones. Patients should also avoid calcium-rich foods.
As soon as the diseased parathyroid gland is surgically removed and the circulating calcium can be normalized, the damage to the affected organs (bones, kidneys, heart) also ends.
The pain, which can last for years, very often disappears immediately after the operation. Patients often feel much more vital, alert and less exhausted after a few weeks.
Doctors who treat hyperparathyroidism are first and foremost endocrinologists (proper diagnosis).
Surgery should be performed by a surgeon with proven expertise in thyroid and parathyroid surgery. High case numbers of operations increase expertise and reduce complications. This fact has been scientifically proven several times in recent years.
