Calcium and Parathyroid Disorders

Overview

What are parathyroid disorders?

Parathyroid disorders can cause abnormally high, or low, levels of calcium and phosphorus in the blood. These disorders cause several serious health problems including: brittle bones, fatigue, kidney stones, weakness, and other health issues. 

What are parathyroid glands?

Your four parathyroid glands are each about the size of a rice grain. Located near the thyroid gland, they are part of the body’s endocrine system. The endocrine system produces and secretes hormones into the blood. Hormones control most bodily functions such as growth, reproduction, and metabolism.

What are the functions of parathyroid glands?

When the parathyroid glands are functioning properly, they sense when calcium and phosphorus levels are too low or too high. When they’re too low, the glands release parathyroid hormone (PTH). This causes the bones to release calcium into the bloodstream. PTH also signals the kidneys to increase vitamin D production to increase calcium absorption in the intestines. If calcium is too high, PTH production and secretion decreases.  

Why do we need calcium?

Calcium and phosphorus are important for muscle contractions and to transmit nerve signals. It also keeps bones and teeth healthy.

Causes

What causes parathyroid disorders?

In general, parathyroid disorders happen when PTH levels are too high or too low. Specific parathyroid disorders include hyperparathyroidism and hypoparathyroidism.

What is hyperparathyroidism?

Hyperparathyroidism is an overactive parathyroid gland that produces too much PTH. It is usually caused by an enlargement of one or more parathyroid glands. Too much PTH causes blood calcium to rise (hypercalcemia). Your body releases more calcium into the blood from your bones; intestines absorb more calcium from food sources; and kidneys retain calcium and send it back into your bloodstream instead of secreting it in urine. 

There are two types of hyperparathyroidism, primary and secondary.

Primary hyperparathyroidism is caused when your parathyroid glands produce and release too much PTH. Overproduction of PTH is how your body works to keep calcium levels normal.

Causes can include:

• A benign growth on one parathyroid gland is the most common cause, causing the gland to overreact and make more PTH
• Enlargement of two or more parathyroid glands (hyperplasia)
• Radiation to the neck area
• Taking lithium
• Cancer of the parathyroid gland
• Genetic conditions  

Secondary hyperparathyroidism is caused by another condition in the body that lowers calcium levels. This causes the parathyroid to overwork and compensate for calcium loss. Although it initially decreases calcium levels, over time, PTH levels can increase. Conditions causing it include:

• Severe calcium and/or vitamin D deficiencies
• Chronic kidney disease or kidney failure

Hypoparathyroidism — the opposite of hyperparathyroidism — happens when the parathyroid glands don’t produce enough PTH. It can be caused by:

• Surgery to remove or inadvertent damage to the glands during surgery. This is the most common cause, and can happen years after neck surgery
• Autoimmune disease or endocrine conditions such as Addison’s disease, which can decrease adrenal gland hormone production
• Acute illness, including kidney disease and pancreatitis
• Low levels of magnesium in the blood
• Cancer radiation treatment of face or neck
• Genetic problems, including being born without parathyroid glands or glands that don’t work correctly  

Who’s at highest risk for parathyroid disorders?

Hypoparathyroidism is much less common than hyperparathyroidism. 

You have a higher risk of hyperparathyroidism if you:

• Are female — women are twice as likely as men to be one of the more than 100,000 new cases of hyperparathyroidism diagnosed in the United States every year.  
• Are over age 50
• Are postmenopausal 
• Have had neck radiation

Symptoms

What are the symptoms of parathyroid disorders?

Early in the disease, there may be no symptoms. If symptoms occur, it’s because of damage to or dysfunction in other parts of the body, due to the long-term effects of too much calcium in the blood and too little calcium in your bones.

Symptoms of mild hyperparathyroidism can include:

• Joint and bone pain
• Muscle weakness
• Fatigue
• Depression and anxiety
• Trouble concentrating and memory problems
• Loss of appetite
• Stomach pain
• Difficulty sleeping

Symptoms of more severe hyperparathyroidism include:

• Osteoporosis, which causes bones to break easily, and also contributes to kidney stones, decreased kidney function, heart disease, pancreatitis, increased stomach-acid secretion and ulcers
• Heart disease and high blood pressure
• Bone pain
• Kidney stones or reduced kidney function
• Nausea and vomiting
• Increased thirst and increased urination
• Constipation
• Confusion and forgetfulness

Symptoms of hypoparathyroidism may include:

• Muscle aches or cramps
• Tingling or burning in fingertips, toes and lips
• Twitching or muscle spasms around the mouth, hands, arms and throat
• Nerve function problems
• Fatigue
• Hair loss
• Dry, course skin
• Brittle nails
• Unusual movements 
• Depression or anxiety

Some symptoms of hypoparathyroidism, which cannot be reversed with calcium and vitamin D supplementation, include:

• Stunted growth
• Slow mental development in children  
• Clouded vision due to cataracts
• Calcium deposits in the brain that can cause balance problems and seizures

Diagnosis

How are parathyroid disorders diagnosed?

Symptoms can be absent, or too vague to notice. If symptoms are present, they are common to many other conditions and a parathyroid disorder can be easily missed. 

Your doctor will start by taking your health history and symptoms, and doing a physical exam. Additional test include:

• Blood work to determine calcium, phosphorus and PTH levels
• Tests to check for enlargement of, or growths on, your parathyroid gland
• Blood tests to check vitamin D levels, and if your kidneys are working properly
• Ultrasound to check for kidney stones
• Bone density test to check for bone loss
• Urine may be collected for 24 hours to measure calcium levels
• If a parathyroid disorder is confirmed, MRI or CT scans may be included

Treatments

How are parathyroid disorders treated?

For milder hyperparathyroidism cases, the only treatment may be:

• Regular monitoring of your health to check calcium and phosphorus levels
• Check for bone loss
• Vitamin D replacement
• Self care that includes drinking a lot of water, staying active to keep bones strong, and avoiding thiazide diuretics and lithium  

If your parathyroid gland is enlarged, or your symptoms severe, you may need:

• Surgery, which can cure almost all (95%) of hyperparathyroidism 
• Regular checks of your PTH level after surgery
• Bone density test every year
• Medications to control PTH production, or to prevent calcium loss from bones
• Postmenopausal women may take hormone replacement therapy to help bones retain calcium or other bone specific medications

Treatment for hypoparathyroidism is calcium and phosphorus supplements to normalize your levels. Depending on the cause, you may need to take supplements for life.

At Inland Endocrine, we are highly trained specialists who provide the individual care and attention that will speed your recovery from parathyroid disorders. Call today for an appointment with Inland Endocrine’s treatment team.

References

University of Michigan Health. N.d. Parathyroid Disorders. Retrieved 7-7-21, {https://www.uofmhealth.org/conditions-treatments/endocrinology-diabetes-and-metabolism/parathyroid-disorders}

Cleveland Clinic. N.d. Hyperparathyroidism. Retrieved 7-7-21,  {https://my.clevelandclinic.org/health/diseases/14454-hyperparathyroidism}

Michels, TC and Kelly, KM. 2013. Parathyroid Disorders. American Family Physician. Retrieved 7-8-2021, {https://www.aafp.org/afp/2013/0815/p249.html}

Mayo Clinic. 2020. Hyperparathyroidism. Retrieved 7-8-2021, {https://www.mayoclinic.org/diseases-conditions/hyperparathyroidism/symptoms-causes/syc-20356194}

Mayo Clinic. 2020. Hypoparathyroidism. Retrieved 7-8-2021, 

{https://www.mayoclinic.org/diseases-conditions/hypoparathyroidism/symptoms-causes/syc-20355375}