Parathyroid Gland

What are the parathyroid glands?

Your parathyroid glands are four pea-sized endocrine glands that are embedded within the back side of your thyroid. They produce and release parathyroid hormone (PTH). This hormone is responsible for controlling blood calcium levels.

How many parathyroid glands are there?

Most people have four parathyroid glands. But studies show that some people have fewer or more than four.

What is the function of the parathyroid glands?

Your parathyroid glands have one job: making and releasing parathyroid hormone (PTH). Together, PTH and another hormone — calcitonin — tightly control the levels of calcium in your bloodstream. Having too much or too little calcium in your blood can be associated with health issues.

Calcium is one of the most important and common minerals in your body. About 99% of your body’s calcium is stored in your bones and teeth, while the other 1% of it circulates in your blood. Although it may be a small amount, the calcium in your blood is essential and helps:

• Your nerves function properly.
• Make your muscles squeeze together (contract) so you can move.
• Your blood clot if you’re bleeding.
• Your heart work properly.

Vitamin D also plays an important role in maintaining blood calcium levels because your body needs it to absorb calcium.

Where are the parathyroid glands located?

Most people (around 80%) have four parathyroid glands embedded behind their thyroid gland — the butterfly-shaped gland in your neck. There are typically two parathyroid glands within each “wing” of your thyroid.

Sometimes, your parathyroid glands are located along your esophagus in your neck or in your chest (in your mediastinum, specifically). Healthcare providers call these ectopic (in an abnormal place) parathyroid glands. Around 16% of people have ectopic parathyroid glands.

Ectopic parathyroid glands usually aren’t a cause for concern. But if one or more are releasing too much PTH and you need to have them removed, it may be difficult for your healthcare provider to find them at first.

What do parathyroid glands look like?

Your parathyroid glands are tiny — each about the size and shape of a pea. In some people, parathyroid glands may become overactive and enlarged.

What conditions affect the parathyroid glands?

The two main health conditions involving your parathyroid glands are hyperparathyroidism and hypoparathyroidism.

Hyperparathyroidism

Hyperparathyroidism happens when one or more of your parathyroid glands become overactive and release too much parathyroid hormone.

Your parathyroid glands may do this naturally:

• In response to illnesses.
• If you have low vitamin D.
• When you have kidney function issues to help maintain normal calcium levels in your blood.

Healthcare providers call this secondary hyperparathyroidism. If this process lasts for a long time, it could lead to other health issues.

In other cases, your parathyroid glands may be overactive in a way that causes the levels of calcium in your blood to rise (hypercalcemia). Providers call this primary hyperparathyroidism. It happens when there’s something directly affecting your parathyroid glands. About 100,000 people in the United States develop it each year.

Since providers often discover hypercalcemia in its early stage, most people don’t have symptoms from primary hyperparathyroidism.

More severe and/or long-term cases of hypercalcemia may cause the following symptoms:

• More frequent urination.
• Excessive thirst (polydipsia).
• Fatigue.
• Bone pain.
• Headaches.
• Nausea and vomiting.
• Constipation.
• Decrease in appetite.
• Forgetfulness, depression or irritability.
• Muscle aches, weakness, cramping and/or twitches.

Parathyroid adenoma

A parathyroid adenoma is a benign (noncancerous) growth that appears on one or more of your parathyroid glands. It’s the most common cause of primary hyperparathyroidism.

Parathyroid cancer

Parathyroid cancer can also cause primary hyperparathyroidism. But It’s very rare. Parathyroid cancer accounts for 0.005% of all cancers and 0.5% to 1% of all parathyroid conditions.

Hypoparathyroidism

Hypoparathyroidism is a rare condition that happens when you have low levels of parathyroid hormone in your blood. This causes you to have low levels of calcium (hypocalcemia) and high levels of phosphorous (hyperphosphatemia) in your blood.

Approximately 75% of hypoparathyroidism cases are from accidental damage to your parathyroid glands from neck or thyroid surgery. There are other causes, too, like certain genetic and autoimmune conditions.

If the cause isn’t due to surgery, in most cases, hypoparathyroidism progresses very gradually and symptoms can be mild. Symptoms include:

• Tingling in your lips, fingers and toes.
• Muscle cramps.
• Muscle spasms.
• Abdominal pain.
• “Brain fog” or confusion.
• Abnormal heart rhythm (arrhythmia).
• Brittle nails.
• Dry hair and dry, scaly skin.
• Cataracts.
• Weakened tooth enamel (in children).

What can I do to take care of my parathyroid glands?

Your parathyroid glands are nestled behind your thyroid, so they’re usually not easily damaged or injured. There’s not much you need to do to keep these glands healthy. But there are steps you can take to help your parathyroid glands keep your blood calcium level in a healthy range:

• Make sure you’re getting enough vitamin D: Vitamin D is important for keeping your blood calcium levels stable. Ask your healthcare provider if you need to take a vitamin D supplement.
• Make sure you’re consuming enough calcium in your diet: Having a lack of calcium in your body can contribute to blood calcium issues. Talk to your provider or a registered dietitian if you’re concerned about getting enough calcium in your everyday meals.

A note from Cleveland Clinic

Your parathyroid glands are tiny but mighty glands that are essential for keeping your blood calcium levels stable. Most people don’t think about them — or haven’t heard of them — until there’s an issue. If you have symptoms of high or low blood calcium levels, let your healthcare provider know. They can recommend simple blood tests to get to the bottom of the cause.