The parathyroid glands are four small glands found at the back of the thyroid gland.
Have you ever wondered how our body keeps our calcium levels in check? It’s all thanks to our parathyroid glands — four small glands tucked behind our thyroid. They play a huge role in bone health, nerve function, and even how our muscles work.
Although parathyroid gland disorders are often subtle, abnormal calcium levels, muscle weakness or brittle bones may be indicative of the condition, and worth consulting your doctor. In this article, we’ll walk you through the two main types of parathyroid gland disorders, when to visit a doctor, and what to expect.
Understanding the parathyroid glands
The parathyroid glands are 4 small glands located at the back of the thyroid gland, the butterfly shaped gland in our throat. The main function of these glands are to produce and secrete parathyroid hormone (PTH), the hormone responsible for the regulation of calcium levels in our blood.
When calcium levels in our body become too low, the PTH, along with vitamin D, induce absorption and reabsorption of calcium from the digestive system and the kidneys. In the bone, PTH stimulates osteoclasts to break down bones and release the calcium from the bones into the blood.
As the levels of calcium in the blood increase, both calcium and vitamin D induce a negative feedback loop to the parathyroid hormones to stop producing PTH, preventing a further increase in blood calcium levels.
The main function of the parathyroid glands is to regulate or maintain the homeostasis of calcium levels in our blood. Hence, disorders of the parathyroid hormone will often present as problems caused by an imbalance of serum calcium. Often, this leads to issues in the kidneys, bones, and other conditions.
Parathyroid disorders: what they are and how they’re caused
The parathyroid glands regulate calcium and phosphate balance in the body by producing parathyroid hormone (PTH).
Hyperparathyroidism
Hyperparathyroidism is characterised by overactive parathyroid glands, which result in too much PTH being released. This can lead to dangerously high levels of calcium in the blood. Hyperparathyroidism is mainly categorised as primary and secondary hyperparathyroidism, while tertiary hyperparathyroidism is often considered as a complication of unmanaged hyperparathyroidism.
Primary hyperparathyroidism – Primary hyperparathyroidism is caused by an overproduction of PTH by the parathyroid glands. This can be attributed to parathyroid hyperplasia (overgrowth or enlargement of the parathyroid glands), adenoma (benign parathyroid tumour), or carcinoma (parathyroid cancer).
Secondary hyperparathyroidism – Secondary hyperparathyroidism can be caused by other conditions that lead to a chronic hypocalcaemic state, a condition where your blood calcium levels are abnormally low. This leads to the parathyroid glands making PTH as a response to the low calcium levels. Secondary hyperparathyroidism can be caused by chronic kidney diseases (CKD), calcium deficiency, or vitamin deficiency.
Tertiary hyperparathyroidism – Tertiary hyperparathyroidism is a complication of chronic, untreated hyperparathyroidism. Typically, this is seen in end-stage kidney diseases. The chronically low calcium levels lead to the overgrowth or hyperplasia of the parathyroid gland tissues.
Hypoparathyroidism
On the other hand, hypoparathyroidism is characterised by low productivity of the parathyroid glands. Impaired function of the parathyroid glands can lead to low levels of calcium, high levels of phosphate, and neuromuscular irritability. This condition is uncommon, and can be caused by:
Injuries to the parathyroid hormone, usually during head and neck surgery
Genetic conditions, such as DiGeorge syndrome
Autoimmune diseases
Use of medication, such as immune checkpoint inhibitors
Malnutrition, such as magnesium deficiency
Radiation injury to the parathyroid glands
Other illnesses, such as granulomatous disease
Signs and Symptoms to look out for
Abnormal calcium levels in the body can lead to various signs and symptoms. Common symptoms of parathyroid disorders can include:
Tingling sensation or numbness in the hands and feetHeadacheImpaired visionSeizures Involuntary muscle spasms or contractionsDementiaParkinsonism
Psychiatric symptoms
DepressionAnxietyEmotional instability
DepressionAnxiety
Pulmonary symptoms
BronchospasmLaryngospasmWheezing
Renal symptoms
Polydipsia or increased thirstIncreased urinationRenal colic, characterised by severe sudden pain in the kidneysRenal failure
Ophthalmic symptoms
Cataracts
When our calcium levels are out of balance, our whole body can experience its effects. However, this also makes parathyroid gland disorders hard to identify, and symptoms are often mistaken for other issues.
In most cases, parathyroid disorders are diagnosed incidentally during testing for serum calcium levels when performing tests for renal or bone disorders.
How are parathyroid disorders diagnosed?
Diagnosis of parathyroid disorders typically involve blood tests to measure calcium and PTH levels. Your doctor may perform other tests depending on the symptoms you have at the time of examination. Generally, parathyroid disorders are evaluated based on the following:
Blood tests – Blood tests are important to evaluate the following:
Serum calcium levels – Tests involving calcium levels in the blood can be measured as total serum calcium, or ionised serum calcium. Calcium levels in the blood can indicate whether your symptoms are caused by hypercalcaemia or hypocalcaemia.
PTH levels – PTH levels are also important to differentiate between hyperparathyroidism and hypoparathyroidism. In normal conditions, PTH levels are between 10 – 65 pg/mL.
Parathyroid-related peptide (PTHrP) – PTHrP is a protein produced in the body in very low amounts. Higher levels of PTHrP typically indicate cancers such as squamous cell lung cancer, squamous cell head and neck cancers, and breast cancers. This test is typically done to rule out malignancies.
Vitamin D – Vitamin D tests are done to diagnose vitamin D deficiency.
Imaging scan – Sestamibi parathyroid scintigraphy is a parathyroid scan performed to evaluate the size of the parathyroid glands. This test can be used to look for signs of parathyroid adenoma or hyperplasia.
Neurological exams – Hypoparathyroidism can cause muscle twitches or spasms when the nerves are stimulated. Specific tests used to look for signs of hypoparathyroidism are called the Chvostek sign and the Trousseau sign.
Other tests – Other tests are typically performed to assess bodily functions that may be affected by hypercalcaemia or hypocalcaemia. These can include electrocardiogram to assess cardiac activity, urine tests to look for calciuria, and renal ultrasounds to look for the presence of kidney stones.
How are parathyroid disorders treated?
Parathyroid disorders are treated according to the type of disorder and the possible underlying cause.
Hyperparathyroidism
Primary hyperparathyroidism – Hyperparathyroidism caused by overactive parathyroid glands can be treated with:
Surgery – Surgical therapy is often done via parathyroidectomy, a procedure involving the removal of one or more parathyroid glands. In most patients, parathyroidectomy can effectively bring calcium levels to a normal range and improve bone mineral density.
Medications – When surgical treatment is not ideal, such as in elderly patients, or patients with comorbidities, medical treatment is a suitable alternative. Medications are typically given to treat complications of hyperparathyroidism, such as hypercalcaemia or osteoporosis. Common medications used include bisphosphonates for osteoporosis, and calcimimetics, such as cinacalcet, or phosphates to regulate calcium levels.
Supplements – Vitamin D supplements are also recommended for patients with vitamin D deficiency.
Secondary hyperparathyroidism – Treatment of secondary hyperparathyroidism should involve treatment of the underlying condition or cause of hyperparathyroidism, such as CKD. In addition to that, management of abnormal serum calcium levels are also similar to that of primary hyperparathyroidism.
Medical therapy – Medical treatment of secondary hyperparathyroidism in CKD patients is typically done by managing serum calcium, phosphate, and vitamin D levels. Common medications used include cinacalcet, phosphate binders (aluminium hydroxide, sevelamer hydrochloride, and sevelamer carbonate), as well as vitamin D metabolites (cholecalciferol and ergocalciferol).
Surgery – Parathyroidectomy is often indicated if medical treatment was unsuccessful or if symptoms are refractory to the treatment given. Other indications of surgery for secondary hyperparathyroidism include calciphylaxis, refractory itching, severe hypercalcaemia, high phosphate levels, anaemia, chronically high PTH levels, and extraskeletal calcification.
Tertiary hyperparathyroidism – Treatment for tertiary parathyroidism generally involves addressing the overproduction of parathyroid hormone (PTH) that persists despite correction of the initial cause (usually long-standing secondary hyperparathyroidism in chronic kidney disease patients after renal transplantation). The main focus of treatment is to manage hypercalcaemia and reduce excessive PTH secretion.
Surgery – Surgery is the definitive treatment for tertiary hyperparathyroidism, especially in patients with persistent hypercalcaemia or high PTH calcifications. It is also recommended in patients who experience symptoms like bone pain, pruritus, and soft tissue or vascular calcifications.
Medications – Medications, such as Cinaclet, a calcimimetic agent, can be used to lower serum calcium levels and PTH. Vitamin D analogues and phosphate binders can also be prescribed to stabilise calcium-phosphate metabolism.
Hypoparathyroidism
Treatment of hypoparathyroidism includes:
Supplements – Supplements are useful in patients with hypoparathyroidism. Supplements of calcium and calcitriol, a vitamin D metabolite, are typically recommended to maintain serum calcium levels. Patients with parathyroid gland injuries, such as from head and neck surgical procedures, typically get better within a month following oral calcium and calcitriol treatments.
Hormone replacementtherapy – Hormone replacement with PTH can also be indicated for patients with hypoparathyroidism who struggle with standard therapy using calcium and calcitriol supplements. Palopegteriparatide is a PTH analogue used for this purpose.
When to visit your doctor
You should visit a doctor if you experience signs of parathyroid disorders. The symptoms of parathyroid disorders can also resemble other conditions or disorders which may be more serious, hence it is always recommended to visit a doctor for a proper and comprehensive diagnosis.
Summary
Fatigue, bone aches and mood changes could mean more than just everyday stress. Parathyroid disorders can often fly under the radar, but they can greatly impact your overall health. Thankfully, parathyroid disorders are treatable, and often curable, with the right medical care.
Here at NC Tan Surgery, we believe in delivering precise, patient-focused care. Schedule a consultation with us for a detailed diagnosis and personalised treatment plan.
Frequently Asked Questions
How can I prevent parathyroid gland disorders?
Preventing parathyroid gland disorders can involve:
Taking in enough vitamin D and calcium – Deficiencies of vitamin D and calcium can lead to secondary hyperparathyroidism. Additionally, taking enough vitamin D and calcium also keeps your bones healthy and prevents the risk of osteoporosis.
Managing conditions such as chronic kidney diseases – Managing CKD can reduce the risk of secondary hyperparathyroidism.
Are parathyroid disorders dangerous?
In most cases, the condition is mild to moderate. However, chronic parathyroid disorders can lead to complications that may affect quality of life and increase the risk of mortality and morbidity, such as increased risk of fractures due to osteoporosis.
What happens if parathyroid disorders are left untreated?
Common complications of parathyroid disorders include:
Osteoporosis – Loss of bone mineral density due to high levels of PTH can lead to osteoporosis, this increases the risk of bone fractures from low-impact trauma, such as falling.
Kidney stones – High levels of calcium in the blood can lead to kidney stone formation.
Cardiovascular diseases – Similarly, high levels of calcium in the blood is linked to an increased risk of heart diseases and high blood pressure.
