Hypoparathyroidism (Underactive Parathyroid)

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What is hypoparathyroidism (underactive parathyroid)? 

Hypoparathyroidism (underactive parathyroid) is an uncommon but treatable medical condition in which the parathyroid glands produce abnormally lower levels of parathyroid hormone (PTH). The parathyroid glands are small, pea-sized glands usually located behind the thyroid glands in the neck. They are responsible for balancing the levels of calcium and phosphorus in the body.

Parathyroid hormone plays a crucial role in regulating the level of calcium in the blood and bones. When the parathyroid glands do not produce enough PTH, it can result in several health problems, such as: 

  • Hypocalcaemia: hypocalcaemia is characterised by low calcium levels in the blood, which can cause muscle cramps, tingling or numbness in the extremities, muscle spasms, and severe symptoms like seizures and cardiac arrhythmias.
  • Hyperphosphataemia: hyperphosphataemia is caused by elevated levels of phosphorus in the blood, which can result in the formation of calcium deposits in soft tissues, such as the kidneys, eyes, and blood vessels.
  • Weakened bones: due to loss of calcium from the bones, hypoparathyroidism can result in decreased bone density and increased risk of fractures in the long run. 
parathyroid glands 
The parathyroid glands, located behind the thyroid gland in the neck, control calcium levels in the body.

What causes hypoparathyroidism? 

Hypoparathyroidism may develop as a result of different factors. Some of the most common causes of hypoparathyroidism include:

  • Surgical removal of the parathyroid glands: the surgical removal of parathyroid glands, usually during thyroid surgery, especially in the case of a total or near-total thyroidectomy (link to service page), can result in hypoparathyroidism. The damage to the parathyroid glands during such procedures is one of the common causes of hypoparathyroidism.
  • Autoimmune disorders: certain autoimmune conditions, such as autoimmune polyendocrine syndrome type 1 (APS1) and autoimmune polyendocrine syndrome type 2 (APS2), can cause damage to the parathyroid glands, which may result in decreased parathyroid hormone production.
  • Low levels of magnesium in the blood: the parathyroid glands utilise magnesium for regulating the secretion of parathyroid hormone (PTH), which balances the calcium levels in the body. Insufficient magnesium levels in the blood may cause the parathyroid glands to become less responsive and produce lower levels of PTH, thereby causing hypoparathyroidism.
  • Congenital hypoparathyroidism: certain genetic mutations can affect the functioning and development of the parathyroid glands, which may result in congenital hypoparathyroidism. These genetic mutations can be associated with syndromes like DiGeorge syndrome.
  • Radiation therapy: sometimes, radiation therapy to the neck or head for the treatment of certain cancers may damage the parathyroid glands, which may hinder these glands’ ability to produce sufficient parathyroid hormone and cause hypoparathyroidism. 

The severity of hypoparathyroidism varies based on the underlying cause. The condition may be temporary among some individuals, while it can require lifelong treatment to manage calcium and phosphorous levels among other individuals. 

Individuals with hypoparathyroidism must work closely with their endocrinologist to prevent complications associated with low calcium levels in the body. 

What are the symptoms of hypoparathyroidism? 

Hypoparathyroidism can manifest itself in the form of various symptoms, mainly due to lower levels of calcium in the blood and increased levels of phosphorus. However, the combination and severity of these symptoms may vary from one individual to another. Some of the common symptoms of hypoparathyroidism include: 

  • Tingling or numbness: patients with hypoparathyroidism may experience numbness or tingling, most commonly in their fingers, toes, and around the mouth. 
  • Muscle spasms and cramps: muscle spasms and cramps are one of the most common symptoms associated with hypoparathyroidism. While the patient can experience spasms and cramps in different body parts, it is more common in the feet, hands, and face. 
  • Weakness and fatigue: lower calcium levels in the blood can result in fatigue and muscle weakness. 
  • Seizures: low calcium levels (hypocalcaemia) may even trigger seizures in severe cases. 
  • Cataracts: if left untreated or unmanaged, hypoparathyroidism may increase the risk of developing eye cataracts
  • Hair and skin changes: low calcium levels may cause brittle nails, hair loss, and dry skin among some individuals. 
  • Mood swings: patients with hypoparathyroidism may suffer from anxiety, irritability, or even depression in some cases. 
  • Low bone density: if left untreated, hypoparathyroidism can cause decreased bone density over time, causing an increased risk of fractures. 
  • Painful menstruation among women: female patients with hypoparathyroidism may experience more painful periods. 

 Is hypoparathyroidism painful? 

Hypoparathyroidism itself is not a painful condition. Its primary symptoms are related to low calcium levels in the blood (hypocalcaemia) and increased phosphorus levels. While these symptoms may cause muscle spasms, muscle cramps, weakness, and numbness and can be distressing or uncomfortable, they generally do not cause acute pain. 

However, if left uncontrolled, these complications can lead to certain painful conditions. Untreated hypoparathyroidism may cause calcium deposits in soft tissues, including the eyes, blood vessels, and kidneys. These deposits can result in discomfort or pain and, in some cases, may lead to complications; for example, calcium deposits in the kidney may cause kidney stones. 

If you have hypoparathyroidism and are experiencing pain or discomfort, discuss your symptoms with an endocrinologist to determine the cause and receive appropriate treatment.

Who is at risk of hypoparathyroidism in Singapore? 

Individuals who are at an increased risk of developing hypoparathyroidism often have certain factors or conditions that elevate their susceptibility to the disorder. Risk factors of hypoparathyroidism include:

  • Recent neck surgery, especially involving the thyroid: individuals who have undergone neck surgery recently, especially involving the thyroid, are at a higher risk of developing hypoparathyroidism. The parathyroid glands, responsible for maintaining calcium balance in the body, are located nearby or within the thyroid glands; therefore, neck surgery involving the thyroid glands may inadvertently damage the parathyroid glands, making an individual more susceptible to hypoparathyroidism. 
  • Family history of hypoparathyroidism: individuals with a family history of hypoparathyroidism are more at risk of developing the condition as a genetic predisposition may contribute to the underactivity of the parathyroid glands. 
  • Certain autoimmune or endocrine conditions: certain autoimmune or endocrine disorders can increase the likelihood of developing hypoparathyroidism. For example, an autoimmune disease known as Addison’s disease may decrease the level of hormones produced by the adrenal glands, making an individual more susceptible to hypoparathyroidism. 
  • Age: although hypoparathyroidism can occur among individuals of all ages, it is more common among middle-aged and older individuals.
  • Gender: hypoparathyroidism is slightly more common among women as compared to men.

How is hypoparathyroidism diagnosed? 

A combination of clinical evaluation, blood tests, and imaging studies are utilised to confirm the diagnosis of hypoparathyroidism. 

  • Clinical evaluation: your endocrinologist will take your medical history and conduct a detailed physical examination. They will inquire about your symptoms, family history, and any previous surgeries that include the neck or thyroid area. 
  • Blood tests: blood tests to confirm the diagnosis of hypoparathyroidism include:
    • Calcium levels: it is one of the most common blood tests that check the calcium levels in your blood, which is a hallmark of hypoparathyroidism. 
    • Phosphorus levels: a blood test will be administered to monitor the phosphorus levels in the blood, as elevated blood phosphorus levels are common among patients with hypoparathyroidism. 
    • Magnesium levels: low magnesium levels, also known as hypomagnesaemia, can exacerbate hypoparathyroidism; therefore, your endocrinologist may also check your magnesium levels. 
    • Urine tests: to determine the cause of hypoparathyroidism and assess calcium excretion. 
  • Imaging studies: imaging studies, such as ultrasound (link to service page) or a sestamibi scan, can be utilised to evaluate the condition of the parathyroid glands, especially in cases where the diagnosis remains unclear or if a neck surgery has been conducted recently. 
calcium levels blood test
Blood tests are utilised to assess calcium levels and confirm the diagnosis of hypoparathyroidism.

The combination of low blood calcium levels, low parathyroid hormone levels, and elevated phosphorus levels typically indicates hypoparathyroidism. 

What are the treatment options for hypoparathyroidism in Singapore? 

The primary aim when treating hypoparathyroidism is to maintain healthy and normal calcium and phosphorus levels in the blood and alleviate the symptoms associated with the condition. Therefore, the treatment options for hypoparathyroidism include: 

  • Calcium supplements: calcium supplements, typically in the form of calcium citrate or calcium carbonate, are prescribed to increase the calcium levels in the blood. The dosage is prescribed per an individual’s needs and after monitoring their calcium levels periodically. 
  • Vitamin D supplements: vitamin D helps absorb the calcium in the intestines. Most patients with hypoparathyroidism need vitamin D supplements, usually in the form of calcitriol or alfacalcidol. To avoid raising calcium levels in the blood, your endocrinologist will carefully tailor the dosage of vitamin D supplements as per your body’s requirements. 
  • Magnesium replacement: in case of hypomagnesaemia, magnesium supplements may be prescribed, as low magnesium levels can exacerbate hypoparathyroidism. 
  • Continuous monitoring: regular blood tests may be required as part of the treatment plan to monitor the calcium, phosphorus, and PTH levels in your blood. Regularly conducting these tests is essential for adjusting the dosage of supplements to keep the levels of calcium, phosphorus, and PTH  within the target range. 
  • Lifestyle and diet modifications: patients with hypoparathyroidism must maintain a healthy and nutritious diet that is neither too high nor too low in calcium. They should also limit foods high in phosphorus because excessive phosphorus intake may worsen hypoparathyroidism. You must actively coordinate with your healthcare team for diet management. 
  • Treatment of underlying causes: if hypoparathyroidism is caused by another medical condition, such as an autoimmune disease, you may need to seek treatment for that condition to manage hypoparathyroidism. 
  • Thiazide diuretics: in some instances, thiazide diuretics may be recommended to limit calcium excretion in the urine to control calcium levels. However, their use is rare and is only reserved for specific conditions. 
  • Calcimimetics: calcimimetics are medicines that help regulate the calcium levels in the blood by mimicking the action of PTH on the parathyroid glands. It is usually prescribed when other conventional treatments remain insufficient in managing the condition. 
parathyroid hormone levels blood test
Regular monitoring of parathyroid hormone levels helps effectively manage hypoparathyroidism.

However, it is essential to note that the treatment option for hypoparathyroidism depends on an individual’s condition and the underlying cause and severity of the disease. Therefore, regular follow-up with an endocrinologist is crucial for proper diagnoses and timely treatment. 

If you are suffering from hypoparathyroidism, schedule an appointment with ACE Surgery and Endoscopy to receive personalised treatment tailored to your condition. 

Frequently Asked Questions 

Can hypoparathyroidism be cured?

Hypoparathyroidism is usually a lifelong condition, but it can be effectively managed with medication and lifestyle adjustments. Management aims to control symptoms and maintain normal calcium levels rather than cure the condition.

Can I lead a normal life with hypoparathyroidism?

With proper treatment and management, most individuals with hypoparathyroidism can lead normal, fulfilling lives. It may require ongoing medication and monitoring, but many people effectively control their symptoms.

How often should I have my calcium and PTH levels monitored?

Regular monitoring is crucial. In the initial phase of treatment, frequent testing may be necessary to determine the correct dosage of supplements. Once stable, you'll typically have blood tests every few months to ensure your levels remain in the target range.

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Reyaz Moiz

Dr Reyaz Singaporewalla
Senior Consultant Endocrine and General Surgeon

MBBS (Bom), MS (Surg), DNB (Surg), FRCS (Edin), MMed (Singapore), FRCSEd.