Parathyroid Glands: Function, Location, Calcium Balance and Common Conditions
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What do the parathyroid glands do?
The parathyroid glands are small glands, usually four behind the thyroid, that make parathyroid hormone (PTH) to tightly control blood calcium, which nerves, muscles, clotting and the heart depend on. Too much PTH raises blood calcium, while too little lowers it. Persistent symptoms of high or low calcium, especially after neck surgery, warrant blood tests. [1]
What the research says
Four glands is the usual number, but not the only one. A meta-analysis of 26 studies (7,005 patients; 23,519 glands) found that 81.4% of patients have four parathyroid glands and 15.9% of glands are in ectopic locations: 11.6% in the neck and 4.3% in the mediastinum (Taterra et al., Langenbecks Arch Surg, 2019). [2]
Long-term low PTH after thyroid surgery is uncommon. A meta-analysis of 66 studies (51,096 patients) found a pooled proportion of long-term hypoparathyroidism of 2.4% (95% CI 1.9 to 3.0), with no significant difference between three early calcium and vitamin D supplementation strategies (van Dijk et al., Otolaryngol Head Neck Surg, 2024). [3]
Some surgical factors raise the risk of hypoparathyroidism after thyroid surgery. A systematic review and meta-analysis of 93 studies examined 19 risk factors; total thyroidectomy versus lobectomy, central or lateral neck dissection and female sex were among those significantly associated with transient and permanent hypoparathyroidism (Ning et al., Int J Surg, 2024). [4]
What are the parathyroid glands?
The parathyroid glands are pea-sized endocrine glands embedded within the back side of the thyroid. Most people have four, although some people have fewer or more. To learn about the neighboring gland, read our guide to the thyroid gland. [1]
Their single job is to make and release PTH. PTH and calcitonin work together to control calcium levels in the bloodstream. [1]
Why is calcium important?
About 99% of the body’s calcium is stored in the bones and teeth, while about 1% circulates in the blood. Although the amount in the blood is small, it is essential for several functions. [1]
Blood calcium helps nerves function properly, helps muscles contract so the body can move, supports blood clotting and helps the heart work properly. Vitamin D also helps maintain blood calcium because the body needs vitamin D to absorb calcium. [1]
Calcium-related role | Why it matters |
Nerves | Blood calcium helps nerves function properly. |
Muscles | It helps muscles contract so you can move. |
Blood clotting | It helps blood clot when bleeding occurs. |
Heart | It helps the heart work properly. |
Vitamin D connection | The body needs vitamin D to absorb calcium. |
Where are the parathyroid glands located?
Most people, around 80%, have four parathyroid glands behind the butterfly-shaped thyroid. There are usually two glands within each side, or “wing,” of the thyroid. [1]
Some glands are located along the esophagus in the neck or in the chest, specifically in the mediastinum. These are called ectopic parathyroid glands, and around 16% of parathyroid glands are found in these locations. Ectopic glands usually are not a concern. However, if an ectopic gland releases too much PTH and needs removal, it may be difficult to find.
Location | Description |
Typical location | Behind the thyroid in the neck. |
Typical number | Four glands, usually two on each side of the thyroid. |
Ectopic location | Along the esophagus in the neck or in the chest’s mediastinum. |
Size | Each gland is about the size and shape of a pea. |
What is hyperparathyroidism?
Hyperparathyroidism happens when one or more parathyroid glands become overactive and release too much PTH. For a fuller overview, read our guide to hyperparathyroidism. [1]
Secondary hyperparathyroidism is a response to illness, low vitamin D or kidney-function issues that affect normal blood calcium. If the process lasts a long time, it may lead to other health issues. [1]
Primary hyperparathyroidism occurs when something directly affects the parathyroid glands and raises calcium levels in the blood, a condition called hypercalcemia. About 100,000 people in the United States develop primary hyperparathyroidism each year. [1]
Healthcare professionals often discover hypercalcemia early, so most people do not have symptoms from primary hyperparathyroidism. More severe or long-term cases of hypercalcemia may cause symptoms. [1]
Type | Description |
Secondary hyperparathyroidism | The glands release too much PTH in response to illness, low vitamin D or kidney-function issues. |
Primary hyperparathyroidism | Something directly affects the glands and causes blood calcium to rise. |
What symptoms can high calcium cause?
More severe or long-term hypercalcemia may cause frequent urination, excessive thirst, fatigue, bone pain, headaches, nausea and vomiting, constipation, decreased appetite, forgetfulness, depression or irritability, and muscle aches, weakness, cramping or twitches. Read more in our guide to hypercalcemia. [1]
Possible symptom | Context |
Frequent urination or excessive thirst | Listed among symptoms of more severe or long-term hypercalcemia. |
Fatigue or headaches | Possible symptoms of high calcium. |
Bone pain | Possible symptom of more severe or long-term hypercalcemia. |
Nausea, vomiting or constipation | Digestive symptoms that may occur. |
Appetite or mood changes | Decreased appetite, forgetfulness, depression or irritability may occur. |
Muscle symptoms | Muscle aches, weakness, cramping or twitches may occur. |
A symptom list cannot determine whether high calcium or a parathyroid condition is present. Persistent or concerning symptoms should be discussed with a qualified healthcare professional.
What is a parathyroid adenoma?
A parathyroid adenoma is a benign, or noncancerous, growth on one or more parathyroid glands. It is the most common cause of primary hyperparathyroidism. [1]
What is parathyroid cancer?
Parathyroid cancer can also cause primary hyperparathyroidism, but it is very rare. It accounts for 0.005% of all cancers and 0.5% to 1% of all parathyroid conditions. [1]
What is hypoparathyroidism?
Hypoparathyroidism is a rare condition involving low levels of PTH in the blood. It causes low blood calcium, called hypocalcemia, and high blood phosphorus, called hyperphosphatemia. Our guides to hypoparathyroidism and hypocalcemia explain more. [1]
Approximately 75% of hypoparathyroidism cases are caused by accidental damage to the parathyroid glands during neck or thyroid surgery. Other causes include certain genetic and autoimmune conditions. When hypoparathyroidism is not caused by surgery, it usually progresses gradually and symptoms may be mild. [1]
Feature | Hyperparathyroidism | Hypoparathyroidism |
PTH | Too much PTH is released. | PTH is low. |
Calcium | Primary hyperparathyroidism can raise blood calcium. | Blood calcium is low. |
Phosphorus | Not the defining change. | Blood phosphorus is high. |
Possible context | Illness, low vitamin D, kidney-function issues or a direct gland problem. | Neck or thyroid surgery, genetic conditions or autoimmune conditions. |
What symptoms can low calcium cause?
Symptoms of hypoparathyroidism may include tingling in the lips, fingers and toes; muscle cramps; muscle spasms; abdominal pain; brain fog or confusion; abnormal heart rhythm; brittle nails; dry hair and dry, scaly skin; cataracts; and weakened tooth enamel in children. For background on cramps, see our guide to muscle cramps. [1]
These symptoms can have causes other than low PTH or low calcium. A healthcare professional should interpret symptoms with examination and appropriate testing.
How are parathyroid problems evaluated?
Simple blood tests can help investigate symptoms of high or low blood calcium. The exact evaluation depends on the clinical question and may include calcium-related laboratory testing and other assessments chosen by a healthcare professional. [1]
Evaluation focus | Purpose |
PTH levels | Helps assess the hormone made and released by the parathyroid glands. |
Blood calcium | Helps identify high or low calcium levels. |
Blood phosphorus | Relevant to hypoparathyroidism, which involves high phosphorus. |
Medical history | Important when considering prior neck or thyroid surgery, genetic conditions, autoimmune conditions, illness, vitamin D status or kidney function. |
This overview does not specify every test or diagnostic criterion. Ask the clinician ordering testing what each result means in your situation.
How are parathyroid conditions treated?
High or low blood calcium levels caused by parathyroid problems require treatment, and care depends on the condition and its cause.
A parathyroid adenoma or other overactive gland may be considered for removal when clinically appropriate, and ectopic glands may be harder to locate. Discuss vitamin D supplementation with a healthcare provider when needed, and discuss dietary calcium with a provider or registered dietitian.
Do not start, stop or change calcium or vitamin D supplements based only on this article. The right approach depends on blood levels, kidney function, other conditions and current treatment.
How can you care for your parathyroid glands?
The glands are nestled behind the thyroid and usually are not easily damaged or injured. Two practical care areas are getting enough vitamin D and consuming enough calcium in the diet. [1]
Care area | Guidance |
Vitamin D | Vitamin D helps maintain stable blood calcium; ask a healthcare provider whether a supplement is needed. |
Dietary calcium | A lack of calcium can contribute to blood-calcium issues; discuss concerns with a provider or registered dietitian. |
Medical follow-up | Symptoms of high or low blood calcium should be shared with a healthcare professional, who may recommend blood tests. |
When should you contact a healthcare professional?
Contact a healthcare professional about persistent or concerning symptoms such as excessive thirst, frequent urination, fatigue, bone pain, nausea, vomiting, constipation, confusion, muscle spasms, tingling around the mouth or abnormal heart rhythm. These symptoms do not diagnose a parathyroid condition, but they are reasonable topics for evaluation.
Also mention a history of neck or thyroid surgery, kidney-function problems, low vitamin D, autoimmune conditions or genetic conditions, because these factors are connected with parathyroid disorders.
Seek urgent medical assessment for severe or rapidly worsening symptoms, especially confusion, abnormal heart rhythm, repeated vomiting or symptoms that feel life-threatening. Use local emergency guidance when needed.
Conclusion
The parathyroid glands are tiny endocrine glands, usually four, located behind the thyroid. Their main job is to release PTH, which works with calcitonin to keep blood calcium in a stable range. Calcium supports the nerves, muscles, blood clotting and heart.
Hyperparathyroidism involves too much PTH, while hypoparathyroidism involves too little. Both can affect calcium and require professional evaluation. Use this guide to prepare questions about symptoms, blood tests, vitamin D, dietary calcium and the significance of previous neck surgery. For more clear, compassionate health explainers, explore Rinnit.com’s health library.
Frequently Asked Questions
How many parathyroid glands do most people have?
Most people have four parathyroid glands, although some people have fewer or more.
Where are the parathyroid glands located?
The parathyroid glands are usually embedded behind the thyroid in the neck. Some are located along the esophagus or in the chest’s mediastinum; these are called ectopic glands.
What hormone do the parathyroid glands make?
The parathyroid glands make and release parathyroid hormone, or PTH.
What does PTH do?
PTH helps control blood calcium levels. It works with calcitonin to tightly regulate calcium in the bloodstream.
What is hyperparathyroidism?
Hyperparathyroidism occurs when one or more parathyroid glands become overactive and release too much PTH.
What is hypoparathyroidism?
Hypoparathyroidism is a rare condition involving low PTH, low blood calcium and high blood phosphorus.
Can parathyroid problems cause muscle symptoms?
Yes. Muscle aches, weakness, cramping and twitches may occur with more severe or long-term hypercalcemia, and muscle cramps or spasms with hypoparathyroidism.
Can parathyroid problems cause tingling?
Tingling in the lips, fingers and toes is among the possible symptoms of hypoparathyroidism.
What is a parathyroid adenoma?
A parathyroid adenoma is a benign growth on one or more parathyroid glands and the most common cause of primary hyperparathyroidism.
Does vitamin D affect parathyroid function?
Vitamin D helps the body absorb calcium. Low vitamin D can be associated with secondary hyperparathyroidism.
What should I do about calcium or vitamin D supplements?
Discuss supplements with a healthcare provider. Ask a provider about vitamin D supplementation and discuss dietary calcium concerns with a provider or registered dietitian.
Related Reading
Parathyroidectomy: Surgery, Success Rate and Recovery explains parathyroid surgery and recovery.
Parathyroid Scan (Sestamibi): Finding Overactive Glands Before Surgery explains the scan that finds overactive parathyroid glands before surgery.
References
Cleveland Clinic. Parathyroid Glands: What They Are, Function & Location. Cleveland Clinic. Updated May 13, 2024. https://my.clevelandclinic.org/health/body/parathyroid-gland
Taterra D, Wong LM, Vikse J, et al. The prevalence and anatomy of parathyroid glands: a meta-analysis with implications for parathyroid surgery. Langenbecks Arch Surg. 2019;404(1):63-70. PMID 30762091. https://doi.org/10.1007/s00423-019-01751-8
van Dijk SPJ, van Driel MHE, van Kinschot CMJ, et al. Management of Postthyroidectomy Hypoparathyroidism and Its Effect on Hypocalcemia-Related Complications: A Meta-Analysis. Otolaryngol Head Neck Surg. 2024;170(2):359-372. PMID 38013484. https://doi.org/10.1002/ohn.594
Ning K, Yu Y, Zheng X, et al. Risk factors of transient and permanent hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis. Int J Surg. 2024;110(8):5047-5062. PMID 38652139. https://doi.org/10.1097/JS9.0000000000001475
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional with any questions about a medical condition or treatment.
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