Hyperparathyroidism Definition and Meaning

Hyperparathyroidism is characterized by an increased concentration of parathyroid hormone in the blood. Parathyroid hormone is responsible for regulating the level of calcium in the blood serum. The disease can be completely asymptomatic or cause the most severe symptoms.

What is hyperparathyroidism?

Hyperparathyroidism is usually only discovered by chance during blood tests because the disease is asymptomatic in over 80 percent of cases. Occasionally, however, those affected complain about non-specific symptoms such as tiredness, loss of appetite, mild depressive moods or mild memory disorders. See AbbreviationFinder for abbreviations related to Hyperparathyroidism.

The common feature of all forms of hyperparathyroidism is the increased concentration of parathyroid hormone in the blood. The parathyroid hormone has the task of increasing the calcium concentration in the blood by activating bone resorption and at the same time reducing the phosphate concentration through increased excretion via the kidneys. The antagonist of the parathyroid hormone is the hormone calcitriol.

Both hormones are produced in the parathyroid glands. The parathyroid glands are four small epithelial bodies that are usually located at the upper and lower poles of the thyroid gland. Hyperparathyroidism is not a uniform disease, but a collective term for various disorders with different causes. In most cases, the disease is asymptomatic.

However, a distinction is made between asymptomatic and symptomatic hyperparathyroidism. There are five different forms of this disease, which are divided into primary, secondary, tertiary, quaternary and quintal hyperparathyroidism. The primary form of this disorder is the most common. Quaternary or quintary hyperparathyroidism is very rare.

Causes

All five types of hyperparathyroidism have different causes. In primary hyperparathyroidism, there is usually a benign tumor in one or more parathyroid glands. There are more hormone-producing cells, so hormone release is increased. A benign tumor of the glandular tissue, in this case the parathyroid gland, is called an adenoma.

The adenoma is largely uncoupled from the regulatory circuit within the hormone system. In rare cases, however, a carcinoma of the parathyroid gland can also hide behind it. Normally, an increased calcium level in the blood causes the production of parathyroid hormone to stop by binding to receptors until the calcium level has fallen again.

In the context of primary hyperparathyroidism, however, even slightly increased calcium levels in the blood cannot bring about a significant reduction in hormone production. It only stops here if the values ​​are higher. However, this can lead to a considerable loss of bone substance. Missing minerals in the bones are replaced by connective tissue.

Simultaneous bleeding into the bone substance causes so-called brown tumors to form from merging bone cysts. In secondary hyperparathyroidism, the increased production of parathyroid hormone is provoked by a chronically low level of calcium in the blood. The body tries to balance the calcium level by increasing the formation of parathyroid hormone. However, this does not succeed, resulting in permanent hyperparathyroidism.

Low calcium levels can be caused by vitamin D deficiency, malabsorption of calcium in the gut or renal insufficiency. In the case of renal dysfunction, the phosphates are only insufficiently excreted in the urine. These then bind calcium and thereby lower the calcium level in the blood. Secondary hyperparathyroidism based on renal insufficiency can progress to tertiary hyperparathyroidism.

The tertiary form of the disease, in turn, resembles primary hyperparathyroidism. Chronic renal insufficiency requires a sustained increase in the production of parathyroid hormone in order to increase the level of calcium in the blood. This stimulates the growth of the adrenal glands. As in the case of an adenoma, the glandular tissue is enlarged here, which in turn decouples hormone production from the regulatory circuit.

When kidney damage develops from the effects of primary hyperparathyroidism, the secondary overproduction of parathyroid hormone induced on this basis is referred to as quaternary hyperparathyroidism. After the quaternary hyperparathyroidism has existed for a longer period of time, decoupling also occurs here, with the quintary hyperparathyroidism developing.

Symptoms, Ailments & Signs

Hyperparathyroidism is usually only discovered by chance during blood tests because the disease is asymptomatic in over 80 percent of cases. Occasionally, however, those affected complain about non-specific symptoms such as tiredness, loss of appetite, mild depressive moods or mild memory disorders. Hyperparathyroidism often remains asymptomatic throughout life.

In more severe forms of the disease, however, there is increased bone resorption, which leads to increased bone fragility. Other symptoms include nausea, constipation, increased thirst, increased urine production, or severe loss of appetite. Calcium salts can precipitate in the kidneys, forming kidney stones. In the long term, this leads to renal insufficiency up to complete failure of the kidneys.

Limescale can also be deposited in the arterial blood vessels, which can lead to arterial thrombosis and cardiovascular diseases. In secondary hyperparathyroidism in particular, the development of severe circulatory disorders with extensive necrosis of the skin is possible, since phosphates that are not excreted form insoluble salts with calcium, which can precipitate in the arterioles.

Diagnosis & course of disease

For the right treatment, the exact diagnosis of the present form of hyperparathyroidism is necessary.

Complications

Hyperparathyroidism does not always lead to symptoms or complications. Since the symptoms are not immediately clear in most cases, this disease is unfortunately only recognized relatively late, so that early treatment of hyperparathyroidism is not possible. The person concerned suffers from a loss of appetite, which usually leads to being underweight.

Depression and other mood disorders or memory disorders also occur. It is not uncommon for those affected to feel tired and exhausted, although the tiredness cannot be compensated for by sufficient sleep. This results in bone loss and vomiting and nausea. The patient’s everyday life is severely restricted and negatively influenced by the disease.

In the worst case, this can lead to complete kidney failure. The person concerned is dependent on dialysis until a new donor kidney cannot be found. Necrosis and circulatory disorders also occur in the patient. As a rule, hyperparathyroidism can be combated relatively well with the help of proper nutrition. There are no further complications. Without treatment, life expectancy can be reduced by hyperparathyroidism.

Treatment & Therapy

In the case of asymptomatic hyperparathyroidism, no therapy is often necessary apart from constant monitoring. Otherwise, primary hyperparathyroidism can be completely cured by surgical removal of the adenoma. Non-surgical therapies consist of the administration of bisphosphonates, calcimimetics to inhibit the excretion of parathyroid hormone and a diet low in calcium and rich in vitamin D.

In secondary and quaternary hyperparathyroidism, treatment of the underlying disease predominates. If this can be cured, the overproduction of parathyroid hormone will also disappear. Tertiary hyperparathyroidism is initially treated with medication. If the parathyroid hormone level still does not drop, a partial removal of the epithelium is necessary.

Outlook & Forecast

The prognosis of hyperparathyroidism depends on the form of the disease. Thus, primary parathyroid hyperfunction usually has a very good prognosis when treated. Symptoms go away when the source of the increased hormone production is removed.

Primary hyperparathyroidism is the most common form of overactive parathyroid glands. It is usually caused by a benign adenoma in the parathyroid gland. Since this adenoma produces an increased amount of parathyroid hormone, it should be surgically removed. However, it is not possible to cure the hormonal imbalance without an operation. There are no drugs that can stop or limit the production of parathyroid hormone.

However, there is another form of primary hyperparathyroidism that is genetic and therefore not curable. Here, however, there is only a slight overfunction. Surgery is also required for tertiary and quintessential hyperparathyroidism. Since secondary hyperparathyroidism is triggered by an underlying disease, it can only be successfully treated by treating this disease.

In this way, the hormone imbalance disappears along with the underlying disease. The same applies to the treatment of quaternary hyperparathyroidism. The prognosis of these forms of hyperparathyroidism depends on the success of the therapy for the underlying disease. Kidney stones often develop in long-term hyperparathyroidism. In addition, calcification of muscles and blood vessels can occur, which can lead to further diseases.

Prevention

No preventive measures are known for primary hyperparathyroidism. Other forms of hyperparathyroidism can be caused by kidney disease. Therefore, the risk can be reduced by following the general recommendations for a healthy lifestyle.

Aftercare

After the surgical treatment of hyperparathyroidism, patients often remain under medical supervision for a few days. This allows direct monitoring of the calcium level. Patients are only allowed to go home when the mineral balance is in balance. Doctors recommend regular follow-up checks.

Patients should adhere to this so that correct adjustment is possible. The blood value checks can be used to determine whether the remaining parathyroid tissue is again prone to hyperfunction. Follow-up care should show in good time whether there is a hormone deficiency.

If the condition has not been treated by surgery, staying hydrated is important. This takes place not only during the therapy, but also in the post-treatment phase. Biophosphonates are also used in women who have passed the menopause.

These prevent increased bone fragility. Other active ingredients such as cinacalcet serve to alleviate the symptoms. In any case, those affected should attend regular doctor’s appointments so that any changes can be recognized immediately. A change in lifestyle is generally not necessary, only a certain rest can be advisable. A severe course of the disease may lead to kidney failure: then rapid action is required. That is why patients should know how to interpret their own body signals.