Parathyroid 101 - The Essential Gland You’ve Never Heard Of
- Abby Newberry
- 2 hours ago
- 4 min read
By Abby Newberry
You have likely heard of the Thyroid gland, which is usually situated in the lower front of the neck and regulates the body’s metabolic functions. However, you may not have heard of the Parathyroid gland, a close neighbor of the thyroid but with a completely different function.
These two glands are commonly confused because of their similar-sounding names. Although they are both components of the endocrine system, they are distinct body parts that regulate separate body processes. As a result, the diseases that affect these glands have different symptoms and treatments.
In this article, we will take a closer look at the Parathyroid gland, how it works, and what happens when it malfunctions.
What is the Parathyroid Gland?
The name of the Parathyroid comes from the prefix “para-”, meaning beside or near, due to the gland’s normal location alongside the Thyroid gland. Most people have four Parathyroid glands, each one about the size of a grain of rice.
The main function of the Parathyroid gland is to regulate the amount of calcium circulating in the blood. Calcium is a mineral that is crucial to maintaining proper function of many processes in the human body. You may know that Calcium helps to build strong bones and teeth, but it also plays an important role in muscle contraction, blood clotting, heart rhythm, nerve signal conduction, and maintaining a balance of other electrolytes.
How Does the Parathyroid Work?
The parathyroid gland regulates the body’s calcium through a mechanism known as a negative feedback loop.
When the Parathyroid gland senses low calcium levels in the blood, it releases Parathyroid Hormone (PTH), which stimulates the body to increase blood calcium levels in a number of ways:
PTH causes some of the calcium stored in the bones to be released into the bloodstream. This is called demineralization or resorption.
PTH signals the kidneys, which are normally responsible for excreting excess calcium via the urine, to hold on to more calcium. Vitamin D is also activated in the kidneys.
Vitamin D prompts the small intestine to absorb increased amounts of calcium from dietary sources.
When the Parathyroid gland detects that calcium levels in the blood are sufficient or too high, it stops secreting PTH.
Parathyroid Disease
Certain conditions can cause the parathyroid gland to malfunction by releasing too much or too little PTH.
Hypoparathyroidism
When the Parathyroid gland releases too little PTH, this is known as HYPOparathyroidism. It is a rare condition and generally occurs due to disturbances of the Parathyroid gland during neck/thyroid surgery. However, it may also occur due to genetic mutations or autoimmune disease.
Hypoparathyroidism is generally detected when routine bloodwork shows low calcium and high phosphorus levels. Further testing will confirm low PTH levels in the blood and urine. Treatment usually consists of daily oral calcium and vitamin D supplementation.
Hyperparathyroidism
Much more common is HYPERparathyroidism, when the Parathyroid gland secretes too much PTH. There are several different causes of hyperparathyroidism, and the condition is divided into types based on the underlying cause.
Primary Hyperparathyroidism is caused by enlargement (hyperplasia) of one or more of the Parathyroid glands or a growth on the glands, known as an adenoma. It can also be caused by Parathyroid cancer, although this type of cancer is rare.
As a result of this growth or enlargement, the Parathyroid gland stops responding to signals from the feedback loop and continues to release PTH unchecked. The blood calcium and vitamin D levels thus become too high.
Secondary Hyperparathyroidism is usually due to Chronic Kidney Disease (CKD). In CKD, the kidneys lose the ability to clear phosphate and activate Vitamin D, so blood calcium levels become chronically low. As a result, the Parathyroid gland gets accustomed to overcompensating by pumping out too much PTH, and blood calcium levels become elevated.
Secondary Hyperparathyroidism may also be caused by chronically low Vitamin D levels due to malnutrition, absorption problems, or a lack of sun exposure.
How is Parathyroid Disease Diagnosed?
Your doctor may use labwork involving blood and urine, as well as imaging techniques such as ultrasound or MRI, to diagnose Hyperparathyroidism and confirm whether it is primary or secondary. Your doctor will also ask you if you are experiencing symptoms such as:
Fatigue
Muscle Weakness or Stiffness
Bone or Joint Paint
Depression
Brain Fog
Unexpected Weight Loss
Nausea or Vomiting
Constipation
Increased Thirst
Increased Urge to Urinate
Not all cases of Parathyroid disease are symptomatic. Sometimes labwork can reflect changes before symptoms become apparent.
If left untreated, Hyperparathyroidism can lead to osteoporosis, kidney failure, kidney stones, and diseases of the vascular system, such as high blood pressure, heart attack, and stroke. Because of this, Hyperparathyroidism should always be addressed as soon as possible once it is detected.
Treatment of Overactive Parathyroid
Treatment for the majority of Primary Hyperparathyroidism cases involves surgery to remove the affected Parathyroid gland(s). This is called Parathyroidectomy. Your doctor will also likely recommend certain medications and dietary changes to help balance your body’s levels of calcium, vitamin D, and phosphorus.
Treatment of Secondary Hyperparathyroidism is aimed at treating the underlying cause. The doctor may employ specific types of medications to balance electrolytes, but in severe cases of Chronic Kidney Disease, dialysis or kidney transplant may ultimately be required. If treatment of the underlying cause does not improve Parathyroid function, Parathyroid surgery may still be needed.
When to Seek Medical Help
If you are regularly experiencing the above symptoms, or if you have been diagnosed with Chronic Kidney Disease or nutritional deficiencies, consider asking your health care provider to check your Parathyroid.
If further treatment is needed, your primary provider may refer you to a specialist, such as an endocrinologist or a surgeon, for expert care.
References
Cleveland Clinic. (2024, February 29). Hyperparathyroidism. https://my.clevelandclinic.org/health/diseases/14454-hyperparathyroidism
Cleveland Clinic. (2025, February 17). Parathyroid Hormone. https://my.clevelandclinic.org/health/articles/22355-parathyroid-hormone
Lewis, J.L. (2025, July). Overview of Calcium’s Role in the Body. Merck Manual Consumer Version. https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/electrolyte-balance/overview-of-calcium-s-role-in-the-body
Li, W. & Zhang, F. (2024, September 12). The complex relationship between vitamin D and kidney stones: balance, risks, and prevention strategies. Frontiers in Nutrition, 11. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1435403/full
Mitchell, J. (2021, September 17). The Difference Between Thyroid and Parathyroid Glands. Clayman Thyroid Center. https://www.thyroidcancer.com/blog/the-difference-between-thyroid-and-parathyroid-glands
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