Hypoparathyroidism is a reduction in the activity of the parathyroid glands. There are various reasons for this, which is why there are several types of hypoparathyroidism - primary, secondary and pseudo-hypoparathyroidism. Symptoms of hypoparathyroidism can affect multiple systems and organs. Learn how hypoparathyroidism develops, the symptoms of hypoparathyroidism, the complications of hypoparathyroidism, and the diagnosis and treatment of hypoparathyroidism.

Hypoparathyroidismis a condition that denotes a decreased activity of the parathyroid glands. The effect of hypoparathyroidism is a reduction in the production of parathyroid hormone. Lowering the level of parathyroid hormone has a large impact on the calcium-phosphate balance - the level of calcium decreases and the level of phosphate in the blood increases. Calcium plays a huge role in regulating the work of muscle cells and nerve cells. Calcium deficiency, which is one of the main effects of hypoparathyroidism, causes numerous symptoms in the muscles and nervous system. The effects of hypoparathyroidism affect the functioning of the entire body.

The parathyroid glands are a group of small glands located - as the name suggests - next to the thyroid gland, in front of the neck. A person usually has 4 parathyroid glands with an average size of 3-5 mm. The parathyroid glands are endocrine glands and therefore their main function is to produce hormones. The most important hormone produced by the parathyroid glands is parathyroid hormone (PTH).

The parathyroid glands regulate the levels of calcium and phosphate in the body through parathyroid hormone. The activity of the parathyroid glands primarily affects those organs that play a role in the body's calcium-phosphate balance. These include: bones (the main store of calcium and phosphates), the gastrointestinal tract (a source of calcium and phosphates absorbed from food) and the kidneys (responsible for their excretion with urine). The parathyroid hormone produced by the parathyroid glands increases the level of calcium and lowers the level of phosphate in the blood.

Hypoparathyroidism - types and causes

Hypoparathyroidism can occur in several different ways. We divide hypoparathyroidism into primary - associated with direct dysfunction of the parathyroid glands, and secondary - resulting fromother diseases.

There is also a third type - alleged hypoparathyroidism. This is a condition in which the parathyroid glands function properly and release parathyroid hormone, but its activity is blocked. Pseudo-hypoparathyroidism is also known as parathyroid hormone resistance.

Primary hypoparathyroidism is a condition in which the parathyroid glands are absent or destroyed by a disease process. Lack of parathyroid glands can be a congenital disorder, in which case hypoparathyroidism appears soon after birth.

Sometimes the parathyroid glands can be damaged in the course of chronic conditions. This happens, for example, as a result of some autoimmune diseases, when the human immune system recognizes its own organs as foreign and seeks to destroy them. However, the most common cause of hypoparathyroidism are iatrogenic factors, i.e. factors related to the treatment.

The parathyroid glands are very small glands, often hidden in the parenchyma of the thyroid gland. Any interventions in the neck, such as surgery or previous radiation, can damage the parathyroid glands.

The parathyroid glands are very often removed during an operation to remove the thyroid gland (for example due to cancer) - it is technically impossible to save them during the procedure. Postoperative hypoparathyroidism can be temporary, but if the parathyroid glands are permanently removed, the hypoparathyroidism will be permanent.

Secondary hypoparathyroidism is a condition where the activity of the parathyroid gland is reduced by other medical conditions or metabolic disorders. Secondary hypoparathyroidism is most often caused by elevated levels of calcium in the blood. The parathyroid gland's job is to increase calcium levels.

However, if the calcium level is already high for some reason, the parathyroid glands become temporarily "unnecessary" - their activity ceases and the production of parathyroid hormone is reduced. This condition is called secondary hypoparathyroidism.

Hypoparathyroidism - Symptoms

Hypoparathyroidism leads to a reduction in the level of calcium in the blood. Calcium is one of the most important elements in our body - it is necessary for the proper functioning of all organs and cells.

One of the basic functions of calcium is the regulation of cooperation between two systems: the nervous and the muscular. Calcium is responsible for transmitting nerve impulses to the muscles, thus initiating their contraction.

Early fear of hypoparathyroidism is primarily due to a drop in levelcalcium in the blood. This condition leads to disorders of the neuromuscular regulation, which in medicine are called tetany.

Tetany can manifest as painful muscle spasms (especially of the limbs and face) and a feeling of unpleasant tingling and numbness of the skin around the mouth and on the fingertips. Muscle contractions in the tetany can lead to the characteristic hand shape, so-called. obstetrician's hand (complete extension of the thumb, index and middle finger and complete bend of the 4th and 5th fingers).

An acute attack of tetany may be accompanied by many additional symptoms: nausea and vomiting, visual disturbances, increased breathing rate, headaches and abdominal pain, as well as cardiac arrhythmias.

Full-blown tetany usually develops when there is a sudden and severe drop in blood calcium levels. This happens, for example, due to postoperative hypoparathyroidism, when the removed parathyroid glands suddenly stop producing parathyroid hormone.

It is worth remembering, however, that hypoparathyroidism can develop chronically and gradually. Despite the significant reduction in calcium levels, the body partially adjusts to it - the symptoms of tetany are less intense or almost invisible (the so-called latent tetany).

Hypoparathyroidism can be difficult to diagnose. The clinical picture is dominated by non-specific symptoms, such as headaches, depressed mood or chronic fatigue.

Chronic lowering of calcium levels leads to changes in the skin and its appendages. Long-term hypoparathyroidism can cause dry skin, increased nail brittleness and hair loss. Sometimes the only symptom of chronic hypoparathyroidism is psychiatric disorders (e.g. dementia, depression or neurotic disorders).

Hypoparathyroidism - diagnosis

The diagnosis of hypoparathyroidism is based primarily on the medical history, physical examination and the results of laboratory tests. The parathyroid glands are so small that their imaging tests are not diagnostic useful. It is much more important to assess the activity of the parathyroid glands by measuring the concentration of parathyroid hormone in the blood.

In many cases, hypoparathyroidism can be initially suspected on the basis of a medical history and typical clinical symptoms. For example, surgery in the neck region and subsequent symptoms of tetany indicate a high probability of postoperative hypoparathyroidism. Chronic hypoparathyroidism may be mildly symptomatic, therefore the diagnosis must be supported by objective factorsresults of laboratory tests.

The basis for the diagnosis of hypoparathyroidism are blood tests, in which the levels of calcium, phosphate and parathyroid hormone are determined. In hypoparathyroidism, the parathyroid hormone level drops below the lower limit of normal.

Primary hypoparathyroidism results in a reduction in calcium (hypocalcaemia) and an increase in the level of phosphate (hyperphosphatemia) in the blood. In secondary hypoparathyroidism, parathyroid hormone levels are lowered due to an initially elevated calcium level.

Blood levels of calcium, phosphate and parathyroid hormone are sufficient to make a diagnosis of hypoparathyroidism. Your doctor may order additional urine tests to confirm the diagnosis.

In primary hypoparathyroidism, urinary calcium excretion is increased and phosphate decreased, due to parathyroid hormone deficiency. The administration of parathyroid hormone to the patient leads to an increase in the level of phosphate in the urine. A positive result of such a test, called the Ellsworth-Howard test, confirms the diagnosis of primary hypoparathyroidism.

In the presence of certain clinical symptoms, the doctor may order additional diagnostic tests. Suspicion of arrhythmias is an indication for an ECG and assessment of the heart rate and regularity.

If the patient has muscular symptoms indicating the likelihood of tetany, the doctor may order the so-called EMG (electromyographic) test to assess neuromuscular conduction. During the EMG test, a tetany test can be performed to help confirm or rule out the diagnosis.

Neurological or psychiatric symptoms in the course of hypoparathyroidism are an indication for imaging tests of the central nervous system. A typical picture of hypoparathyroidism are foci of intracerebral calcifications (in the area of ​​the so-called nuclei of the base of the brain).

Hypoparathyroidism - treatment

Treatment of hypoparathyroidism is mainly symptomatic. If there has been irreversible damage or removal of the parathyroid glands, it is impossible to restore their function. The main effects of hypoparathyroidism are calcium deficiency and an excess of phosphate in the blood.

Treatment is aimed at correcting these disorders. In order to achieve the target calcium concentration, chronic intake of calcium preparations is necessary. In case of a very high deficiency and severe clinical symptoms (tetany), it may be necessary to administer calcium intravenously.

Calcium compensation is only possiblewith the correct values ​​of vitamin D3 and magnesium in the blood, therefore, in the case of their deficiencies, appropriate supplementation is necessary.

Excess phosphate is treated by changing the menu (reducing foods with a high content of phosphates, such as milk, cheese, egg yolks, meat products, canned food, fish) and the use of drugs that reduce the absorption of phosphate from the gastrointestinal tract.

If the described methods do not bring the expected results and the calcium-phosphate balance remains unbalanced, a drug supplementing the level of parathyroid hormone - the so-called human recombinant parathyroid hormone (Natpara drug).

The indication for its use is hypoparathyroidism resistant to standard treatment, as well as the presence of complications of the disease. The preparation is registered for use in the European Union, but its biggest disadvantage is its very high price.

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