Hypoparathyroidism: Causes, Symptoms, Risk Factors, Diagnosis, Complications and Treatment

It is a rare endocrine disorder in which the parathyroid glands do not continuously secrete normal parathyroid hormone levels.

These parathyroid glands may generally be present in the human body in several four. However, they may be only two or even six.

They are located in the anterior area of ​​the neck and the back of the thyroid gland.

Parathyroid hormone is the hormone that regulates calcium levels in the body.

If these levels decrease, the cells present in these glands elaborate and release the hormone in the blood and stimulate vitamin D synthesis in the kidney.

This vitamin increases calcium absorption in the intestines, contributing to the increase in the level of calcium present in the blood.

On the other hand, the secretion of the hormone causes the kidney to lose phosphorus and produce a drop in phosphorus levels in the blood, so this hormone is essential to maintain the balance of both calcium and phosphorus.


When the calcium level in the blood is normalized, the hormone is not produced by the parathyroid glands.

Calcium is one of the essential elements in the formation of bones and teeth.

When this element is found, it does not appear in the necessary quantities and in a prolonged way in the organism, so it will prevent the formation of teeth and bones, increasing the risk of fractures.

In the same way, if calcium is found in higher than average amounts and continuously, what is called hyperparathyroidism.

That calcium produced in excess is deposited in the tissues of the kidney, in the walls of the blood vessels, and in the joints, calcifying or hardening them and causing their malfunction.

The limits that are considered normal are given by a concentration of calcium in the blood that varies between 8.5 and 10.5 mg / dL or from 2.1 to 2.6 mol / L.

When there are disorders that cause a reduction or a continued absence of the production of parathyroid hormone, it causes a decrease in the average values ​​in the calcium figures, which is called hypocalcemia.

While high phosphorus values are what is called hyperphosphatemia.


The causes that cause hypoparathyroidism can be divided into three groups, whose classification is made according to conceptual and functional criteria.

Primary Hypoparathyroidism:

This classification includes all those disorders that are provoked in the parathyroid glands.

These disorders are the characteristic deficiencies of the decrease or absence of parathyroid hormone in the blood and its consequents, low calcium levels and high levels of phosphorus.

  • Post-surgical hypoparathyroidism: This is one of the most frequent causes of hypoparathyroidism. They originated when the surgical removal of the parathyroid glands is performed due to accidental damage or necessary, as in the case of a recommended treatment for respiratory diseases. The thyroid gland, or in treatments for the throat or neck cancer.
  • Autoimmune disease: The body’s immune system can generate antibodies that act against the parathyroid tissues and try to block them as if they were foreign bodies. In this process, the parathyroid glands usually suspend the production of parathyroid hormone.
  • Hereditary hypoparathyroidism:  The absence of parathyroid glands can be of congenital origin from birth, as is the case of Di George syndrome. Some instances of hereditary hypoparathyroidism can be related to hormonal insufficiencies in other endocrine glands, such as the thyroid gland, the adrenal glands, and the pancreas, in the case of diabetes mellitus.
  • Radioactive treatment for cancer in the face or neck: Radiation treatments can destroy the parathyroid glands; this condition occurs when radiotherapy treatments are performed on the front and neck or with radioactive iodine.

Secondary Hypoparathyroidism:

Low levels of Magnesium or hypomagnesemia in the blood cause hypocalcemia since normal levels of Magnesium are required for optimal secretion of parathyroid hormone.


In this case, the parathyroid hormone is made and released into the blood, but this hormone is not practical because the organs where it has to act are the bones and kidneys.

They do not respond to the effects of the hormone, so even when it is segregating, there is little calcium in the blood.

This induces the glands to produce even more hormones, but this is still ineffective; it is as if it were not being manufactured in the right amounts.

There are no hormones for “true” hypoparathyroidism, or they occur in tiny amounts.

In pseudohypoparathyroidism, it is a hereditary disorder characterized by signs and symptoms similar to hypoparathyroidism but associated with characteristic faults of skeletal development.


The levels of calcium in the blood decrease and cause the symptoms of hypoparathyroidism.

When the calcium decreases occur little significant and for a prolonged period.

The symptoms that appear are of very little intensity, but if this decrease in calcium is considerable or abrupt, the symptoms are of greater magnitude.

Hypocalcemia presents symptoms in cases of primary hypoparathyroidism, while pseudohypoparathyroidism usually appears in both forms.

Symptoms in the case of secondary hypoparathyroidism are associated with the decline of Magnesium in the blood.

Usually, hypocalcemia occurs in hereditary hypoparathyroidism and pseudohypoparathyroidism gradually and is associated with deterioration in the development of the sign that does not happen in the other types of hypoparathyroidism.

The typical symptoms that occur when hypocalcemia occurs are the following:

Neuromuscular alterations: When there is a decrease in calcium in the blood, there is an increase in the excitability of the muscles and innervation of the nerves.

This gives rise to spasms in the muscles, sensations of tingling, and cramps around the mouth, in the arms and throat that affect the larynx, causing breathing difficulties, spasms in the hands and feet; they can even produce seizures, especially in the case of children.

These signs of Tetany are known as signs of Chvostek and Trousseau.

Mental alterations: These alterations occur from irritability to levels of depression, neurosis, and psychosis. The state of consciousness diminished.

Alterations in the central nervous system: There may be episodes of parkinsonism, memory loss, and multiple involuntary movements in the extremities.

In some cases, individuals with maintained hypocalcemia may present intracranial calcifications visible by X-rays, which justify the presence of parkinsonian type syndromes.

The cardiac alterations: This deficiency produces some anomalies in what refers to the conduction of the electrical stimulus in the heart, and they manifest in the form of arrhythmias, prolongations in the QT interval, alterations of the T wave, and cardiac blocks. Cardiac insufficiencies may also occur.

Alterations in the skin and the accessories: Symptoms appear as dry and scaly skin, brittle nails, and dry and rough hair. Symptoms such as alopecia may also occur.

Skin infections and fungal infections such as candidiasis occur more frequently. These alterations arise especially in cases of hereditary hypoparathyroidism when it is associated with insufficiencies of other endocrine glands.

Ocular alterations: In hypocalcemias that have a long duration, the appearance of cataracts is observed due to the modifications of the lens.

In children, the appearance of dental anomalies such as defective enamels, little dental development, and a delay in the eruption of the teeth is commonplace.

There are usually alterations according to, for example, osteomalacia, rickets, and skeletal deformities.

Seizures or breathing difficulties occur, which are two factors that represent complications in hypoparathyroidism.

Risk factor’s

Among the factors that can increase the risk of suffering from hypoparathyroidism include:

  • Undergo neck surgery that involves the thyroid.
  • Possess genetic predisposition to hypoparathyroidism.
  • Suffering from certain autoimmune or endocrine disorders, such as Addison’s disease, which induces the adrenal glands to significantly reduce the number of hormones they produce.



The diagnosis of hypoparathyroidism is based on low calcium levels in the blood.

The values ​​of parathyroid hormone and phosphorus will vary depending on the cause of hypoparathyroidism.

In the case of primary hypoparathyroidism, blood calcium has low levels and phosphorus levels high, and parathyroid hormone is absent or very low.

In the case of a magnesium deficiency, the levels of calcium and phosphorus in the blood are low, and the stories of the parathyroid hormone are scarce or absent.

When pseudohypoparathyroidism occurs, there is very little calcium and very little phosphorus in the blood.

Parathyroid hormone is high; in this case, hypophosphatemia is more accentuated than hypocalcemia because there is a greater secretion of parathyroid hormone.

I am presenting partial effectiveness in elevating the calcium in the blood and favoring the excretion of phosphorus in the kidney.

If there is a suspicion that the cause of hypoparathyroidism is due to a vitamin D deficiency, its blood values ​​should be analyzed, which will be low in most cases.

Urine tests also reveal variations in phosphorus and calcium values.

The clinical history:

The physical examination and the patient’s interrogation will help discover the origin of hypoparathyroidism and request studies for the differential diagnosis.

Examples are nutritional deficiency, kidney failure, intestinal disorders, surgical neck surgery, history of seizure disorder, and developmental defects, especially in childhood and adolescence.

Rickets and various neuromuscular syndromes and deformities are also observed.


In the case of primary hypoparathyroidism, techniques are used to detect the functioning of the parathyroid glands or the partial or total lack thereof.

These include ultrasound, computed tomography, the magnetic resonance of the neck, and scintigraphy with the help of technetium isotopes such as 99Tc, which allows us to know if these glands are working.

Other techniques such as bone density of the lumbar and hip spine can be indicated to observe the repercussions of hypoparathyroidism at the bone level.


Hypoparathyroidism can lead to various complications.

Reversible complications:

These complications are due to low calcium levels, which are likely to improve with treatment:

  • When these spasms occur at the throat level, Tetany, spasms, and cramps can interfere with breathing and create an emergency.
  • Paresthesias or tingling
  • Loss of consciousness with epilepsy.
  • Malformation in the teeth.
  • Alteration of renal functions.
  • Arrhythmias, fainting, and heart failure.

Irreversible complications:

With diagnosis and proper treatment, they can be prevented, but they will not improve once they occur.

  • The delays in growth.
  • The slow mental development in children.
  • Calcium deposits in the brain.
  • The appearance of cataracts.


The main objective of the treatment is to normalize the levels of calcium and phosphorus in the body, relieving the symptoms.

Oral treatments:

  • Oral administration of calcium supplements may increase calcium levels in the blood, but they can cause gastrointestinal side effects such as constipation in high doses.
  • Administration of Vitamin D high doses of vitamin D can help the body absorb calcium and eliminate phosphorus.
  • Parathyroid hormone (Natpara), this injection is administered 24 hours to treat low calcium levels caused by hyperparathyroidism.


It is advisable to make a diet based on:

  • Calcium: With the consumption of dairy products, green leafy vegetables, and foods made with added calcium, such as orange juice and breakfast cereals.
  • Low phosphorus content: Avoid gaseous drinks, those containing phosphoric acid, restricting the consumption of hard cheeses, meats, and whole grains.

Intravenous infusions:

For immediate relief of symptoms, calcium is recommended by intravenous infusion, continuing with a calcium and vitamin D oral treatment.


Blood tests must be done regularly to control calcium and phosphorus levels.

Because hypoparathyroidism is a chronic disorder, treatment is usually lifelong; doses of calcium supplements will be adjusted according to what calcium levels reflect.